? sites/default/modules
? sites/default/settings.php
Index: includes/actions.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/actions.inc,v
retrieving revision 1.22
diff -u -p -r1.22 actions.inc
--- includes/actions.inc	8 Nov 2008 07:28:03 -0000	1.22
+++ includes/actions.inc	19 Nov 2008 19:08:18 -0000
@@ -71,7 +71,7 @@ function actions_do($action_ids, $object
       $query->condition('aid', $conditions, 'IN');
       $result = $query->execute();
       foreach ($result as $action) {
-        $actions[$action->aid] = $action->parameters ? unserialize($action->parameters) : array();
+        $actions[$action->aid] = ($action->parameters != 'default') ? unserialize($action->parameters) : array();
         $actions[$action->aid]['callback'] = $action->callback;
         $actions[$action->aid]['type'] = $action->type;
       }
@@ -180,7 +180,7 @@ function actions_list($reset = FALSE) {
 function actions_get_all_actions() {
   $actions = db_query("SELECT aid, type, callback, parameters, description FROM {actions}")->fetchAllAssoc('aid', PDO::FETCH_ASSOC);
   foreach ($actions as &$action) {
-    $action['configurable'] = (bool) $action['parameters'];
+    $action['configurable'] = (bool) ($action['parameters'] != 'default');
     unset($action['parameters']);
     unset($action['aid']);
   }
@@ -236,7 +236,7 @@ function actions_function_lookup($hash) 
   }
 
   // Must be an instance; must check database.
-  return db_query("SELECT aid FROM {actions} WHERE MD5(aid) = :hash AND parameters <> ''", array(':hash' => $hash))->fetchField();
+  return db_query("SELECT aid FROM {actions} WHERE MD5(aid) = :hash AND parameters <> 'default'", array(':hash' => $hash))->fetchField();
 }
 
 /**
@@ -251,7 +251,7 @@ function actions_synchronize($actions_in
   if (!$actions_in_code) {
     $actions_in_code = actions_list(TRUE);
   }
-  $actions_in_db = db_query("SELECT aid, callback, description FROM {actions} WHERE parameters = ''")->fetchAllAssoc('callback', PDO::FETCH_ASSOC);
+  $actions_in_db = db_query("SELECT aid, callback, description FROM {actions} WHERE parameters = 'default'")->fetchAllAssoc('callback', PDO::FETCH_ASSOC);
 
   // Go through all the actions provided by modules.
   foreach ($actions_in_code as $callback => $array) {
@@ -269,7 +269,7 @@ function actions_synchronize($actions_in
             'aid' => $callback,
             'type' => $array['type'],
             'callback' => $callback,
-            'parameters' => '',
+            'parameters' => 'default',
             'description' => $array['description'],
             ))
           ->execute();
Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.304
diff -u -p -r1.304 form.inc
--- includes/form.inc	15 Nov 2008 15:32:36 -0000	1.304
+++ includes/form.inc	19 Nov 2008 19:08:19 -0000
@@ -2614,7 +2614,8 @@ function batch_process($redirect = NULL,
       // at least an empty string for the (not null) 'token' column.
       $batch['id'] = db_insert('batch')
         ->fields(array(
-          'token' => '',
+          // token will soon replace with db_update().
+          'token' => 'default',
           'timestamp' => REQUEST_TIME,
         ))
         ->execute();
Index: includes/locale.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/locale.inc,v
retrieving revision 1.195
diff -u -p -r1.195 locale.inc
--- includes/locale.inc	16 Nov 2008 19:41:14 -0000	1.195
+++ includes/locale.inc	19 Nov 2008 19:08:19 -0000
@@ -426,7 +426,7 @@ function locale_languages_delete_form_su
     _locale_rebuild_js($form_state['values']['langcode']);
     // Remove the language.
     db_query("DELETE FROM {languages} WHERE language = '%s'", $form_state['values']['langcode']);
-    db_query("UPDATE {node} SET language = '' WHERE language = '%s'", $form_state['values']['langcode']);
+    db_query("UPDATE {node} SET language = 'default' WHERE language = '%s'", $form_state['values']['langcode']);
     $variables = array('%locale' => $languages[$form_state['values']['langcode']]->name);
     drupal_set_message(t('The language %locale has been removed.', $variables));
     watchdog('locale', 'The language %locale has been removed.', $variables);
@@ -1215,7 +1215,7 @@ function _locale_import_message($message
  * @param $group
  *   Text group to import PO file into (eg. 'default' for interface translations)
  */
-function _locale_import_one_string($op, $value = NULL, $mode = NULL, $lang = NULL, $file = NULL, $group = 'default') {
+function _locale_import_one_string($op, $value = NULL, $mode = NULL, $lang = 'default', $file = NULL, $group = 'default') {
   static $report = array(0, 0, 0);
   static $headerdone = FALSE;
   static $strings = array();
Index: includes/path.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/path.inc,v
retrieving revision 1.28
diff -u -p -r1.28 path.inc
--- includes/path.inc	14 Oct 2008 11:01:08 -0000	1.28
+++ includes/path.inc	19 Nov 2008 19:08:19 -0000
@@ -43,12 +43,12 @@ function drupal_init_path() {
  *   Either a Drupal system path, an aliased path, or FALSE if no path was
  *   found.
  */
-function drupal_lookup_path($action, $path = '', $path_language = '') {
+function drupal_lookup_path($action, $path = '', $path_language = 'default') {
   global $language;
   // $map is an array with language keys, holding arrays of Drupal paths to alias relations
   static $map = array(), $no_src = array(), $count;
 
-  $path_language = $path_language ? $path_language : $language->language;
+  $path_language = ($path_language != 'default') ? $path_language : $language->language;
 
   // Use $count to avoid looking up paths in subsequent calls if there simply are no aliases
   if (!isset($count)) {
@@ -66,7 +66,7 @@ function drupal_lookup_path($action, $pa
         return $map[$path_language][$path];
       }
       // Get the most fitting result falling back with alias without language
-      $alias = db_result(db_query("SELECT dst FROM {url_alias} WHERE src = '%s' AND language IN('%s', '') ORDER BY language DESC", $path, $path_language));
+      $alias = db_result(db_query("SELECT dst FROM {url_alias} WHERE src = '%s' AND language IN('%s', 'default') ORDER BY language DESC", $path, $path_language));
       $map[$path_language][$path] = $alias;
       return $alias;
     }
@@ -77,7 +77,7 @@ function drupal_lookup_path($action, $pa
       $src = '';
       if (!isset($map[$path_language]) || !($src = array_search($path, $map[$path_language]))) {
         // Get the most fitting result falling back with alias without language
-        if ($src = db_result(db_query("SELECT src FROM {url_alias} WHERE dst = '%s' AND language IN('%s', '') ORDER BY language DESC", $path, $path_language))) {
+        if ($src = db_result(db_query("SELECT src FROM {url_alias} WHERE dst = '%s' AND language IN('%s', 'default') ORDER BY language DESC", $path, $path_language))) {
           $map[$path_language][$src] = $path;
         }
         else {
@@ -106,7 +106,7 @@ function drupal_lookup_path($action, $pa
  *   An aliased path if one was found, or the original path if no alias was
  *   found.
  */
-function drupal_get_path_alias($path, $path_language = '') {
+function drupal_get_path_alias($path, $path_language = 'default') {
   $result = $path;
   if ($alias = drupal_lookup_path('alias', $path, $path_language)) {
     $result = $alias;
@@ -126,7 +126,7 @@ function drupal_get_path_alias($path, $p
  *   The internal path represented by the alias, or the original alias if no
  *   internal path was found.
  */
-function drupal_get_normal_path($path, $path_language = '') {
+function drupal_get_normal_path($path, $path_language = 'default') {
   $result = $path;
   if ($src = drupal_lookup_path('source', $path, $path_language)) {
     $result = $src;
Index: includes/database/database.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database/database.inc,v
retrieving revision 1.28
diff -u -p -r1.28 database.inc
--- includes/database/database.inc	15 Nov 2008 08:23:06 -0000	1.28
+++ includes/database/database.inc	19 Nov 2008 19:08:19 -0000
@@ -224,6 +224,8 @@ abstract class DatabaseConnection extend
 
     // Because the other methods don't seem to work right.
     $driver_options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_EXCEPTION;
+    // Empty string is converted to NULL.
+    $driver_options[PDO::ATTR_ORACLE_NULLS] = PDO::NULL_EMPTY_STRING;
 
     // Call PDO::__construct and PDO::setAttribute.
     parent::__construct($dsn, $username, $password, $driver_options);
@@ -454,6 +456,12 @@ abstract class DatabaseConnection extend
     // Use default values if not already set.
     $options += $this->defaultOptions();
 
+    foreach ($args as &$arg) {
+      if ($arg === '') {
+        $arg = NULL;
+      }
+    }
+
     try {
       // We allow either a pre-bound statement object or a literal string.
       // In either case, we want to end up with an executed statement object,
@@ -2243,6 +2251,23 @@ function _db_query_process_args($query, 
     $options['target'] = 'default';
   }
 
+  // TODO: temporary replace '' as NULL here.
+  foreach ($args as &$arg) {
+    if ($arg === '') {
+      $arg = NULL;
+    }
+  }
+
+  // TODO: remove debug
+  openlog("drupal", LOG_PID | LOG_PERROR, LOG_LOCAL0);
+  if (preg_match("/''/", $query)) {
+    syslog(LOG_ERR, "INLINE EMPTY STRING: " . $query);
+  }
+  if (in_array('', $args, TRUE)) {
+    syslog(LOG_ERR, "ARGS EMPTY STRING: " . $query . ' ' . array_search('', $args, TRUE));
+  }
+  closelog();
+
   // Temporary backward-compatibliity hacks.  Remove later.
   $old_query = $query;
   $query = str_replace(array('%n', '%d', '%f', '%b', "'%s'", '%s'), '?', $old_query);
Index: includes/database/mysql/schema.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database/mysql/schema.inc,v
retrieving revision 1.6
diff -u -p -r1.6 schema.inc
--- includes/database/mysql/schema.inc	13 Nov 2008 20:52:13 -0000	1.6
+++ includes/database/mysql/schema.inc	19 Nov 2008 19:08:19 -0000
@@ -73,6 +73,18 @@ class DatabaseSchema_mysql extends Datab
   protected function createFieldSql($name, $spec) {
     $sql = "`" . $name . "` " . $spec['mysql_type'];
 
+    if ($spec['type'] == 'char' || $spec['type'] == 'varchar' || $spec['type'] == 'text' || $spec['type'] == 'blob') {
+      // Not allow default with '', so switch field as nullable.
+      if (isset($spec['default']) && $spec['default'] == '') {
+        unset($spec['default']);
+        $spec['not null'] = FALSE;
+      }
+      // Set field as nullable if no valid default value.
+      if (!isset($spec['default']) && !empty($spec['not null'])) {
+        $spec['not null'] = FALSE;
+      }
+    }
+
     if (isset($spec['length'])) {
       $sql .= '(' . $spec['length'] . ')';
     }
Index: includes/database/pgsql/schema.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database/pgsql/schema.inc,v
retrieving revision 1.2
diff -u -p -r1.2 schema.inc
--- includes/database/pgsql/schema.inc	15 Sep 2008 20:48:07 -0000	1.2
+++ includes/database/pgsql/schema.inc	19 Nov 2008 19:08:19 -0000
@@ -80,6 +80,18 @@ class DatabaseSchema_pgsql extends Datab
   protected function createFieldSql($name, $spec) {
     $sql = $name . ' ' . $spec['pgsql_type'];
 
+    if ($spec['type'] == 'char' || $spec['type'] == 'varchar' || $spec['type'] == 'text' || $spec['type'] == 'blob') {
+      // Not allow default with '', so switch field as nullable.
+      if (isset($spec['default']) && $spec['default'] == '') {
+        unset($spec['default']);
+        $spec['not null'] = FALSE;
+      }
+      // Set field as nullable if no valid default value.
+      if (!isset($spec['default']) && !empty($spec['not null'])) {
+        $spec['not null'] = FALSE;
+      }
+    }
+
     if ($spec['type'] == 'serial') {
       unset($spec['not null']);
     }
Index: modules/aggregator/aggregator.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/aggregator/aggregator.install,v
retrieving revision 1.19
diff -u -p -r1.19 aggregator.install
--- modules/aggregator/aggregator.install	15 Nov 2008 13:01:04 -0000	1.19
+++ modules/aggregator/aggregator.install	19 Nov 2008 19:08:19 -0000
@@ -37,13 +37,12 @@ function aggregator_schema() {
       'title' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Title of the category.',
       ),
       'description' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
         'description' => 'Description of the category',
       ),
@@ -116,15 +115,13 @@ function aggregator_schema() {
       'title' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Title of the feed.',
       ),
       'url' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'URL to the feed.',
       ),
       'refresh' => array(
@@ -142,34 +139,31 @@ function aggregator_schema() {
       'link' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'The parent website of the feed; comes from the &lt;link&gt; element in the feed.',
       ),
       'description' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
         'description' => "The parent website's description; comes from the &lt;description&gt; element in the feed.",
       ),
       'image' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
         'description' => 'An image representing the feed.',
       ),
       'hash' => array(
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Calculated md5 hash of the feed data, used for validating cache.',
       ),
       'etag' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Entity tag HTTP response header, used for validating cache.',
       ),
       'modified' => array(
@@ -210,27 +204,24 @@ function aggregator_schema() {
       'title' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Title of the feed item.',
       ),
       'link' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Link to the feed item.',
       ),
       'author' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Author of the feed item.',
       ),
       'description' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
         'description' => 'Body of the feed item.',
       ),
@@ -256,6 +247,11 @@ function aggregator_schema() {
 }
 
 /**
+ * @defgroup updates-6.x-to-7.x Aggregator updates from 6.x to 7.x
+ * @{
+ */
+
+/**
  * Add hash column to aggregator_feed table.
  */
 function aggregator_update_7000() {
@@ -263,3 +259,104 @@ function aggregator_update_7000() {
   db_add_field($ret, 'aggregator_feed', 'hash', array('type' => 'varchar', 'length' => 32, 'not null' => TRUE, 'default' => ''));
   return $ret;
 }
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function aggregator_update_7001() {
+  $ret = array();
+
+  $schema['aggregator_category'] = array(
+    'fields' => array(
+      'title' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'description' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+    ),
+  );
+
+  $schema['aggregator_feed'] = array(
+    'fields' => array(
+      'title' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'url' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'link' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'description' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+      'image' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+      'hash' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+      'etag' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['aggregator_item'] = array(
+    'fields' => array(
+      'title' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'link' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'author' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'description' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/block/block.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/block/block.install,v
retrieving revision 1.14
diff -u -p -r1.14 block.install
--- modules/block/block.install	15 Nov 2008 13:01:04 -0000	1.14
+++ modules/block/block.install	19 Nov 2008 19:08:19 -0000
@@ -16,8 +16,7 @@ function block_schema() {
       'module' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t("The module from which the block originates; for example, 'user' for the Who's Online block, and 'block' for any custom blocks."),
       ),
       'delta' => array(
@@ -30,8 +29,7 @@ function block_schema() {
       'theme' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('The theme under which the block settings apply.'),
       ),
       'status' => array(
@@ -51,8 +49,7 @@ function block_schema() {
       'region' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Theme region within which the block is set.'),
       ),
       'custom' => array(
@@ -71,14 +68,13 @@ function block_schema() {
       ),
       'pages' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => t('Contents of the "Pages" block; contains either a list of paths on which to include/exclude the block or PHP code, depending on "visibility" setting.'),
       ),
       'title' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Custom title for the block. (Empty string will use block default title, &lt;none&gt; will remove the title, text will cause block to use specified title.)'),
       ),
       'cache' => array(
@@ -104,13 +100,13 @@ function block_schema() {
       'module' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => t("The block's origin module, from {block}.module."),
       ),
       'delta' => array(
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => t("The block's unique delta within module, from {block}.delta."),
       ),
       'rid' => array(
@@ -144,8 +140,7 @@ function block_schema() {
       'info' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => t('Block description.'),
       ),
       'format' => array(
@@ -167,3 +162,85 @@ function block_schema() {
 
   return $schema;
 }
+
+/**
+ * @defgroup updates-6.x-to-7.x Block updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function block_update_7001() {
+  $ret = array();
+
+  $schema['block'] = array(
+    'fields' => array(
+      'module' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'theme' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'region' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'pages' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+      ),
+      'title' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['block_role'] = array(
+    'fields' => array(
+      'module' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'delta' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['box'] = array(
+    'fields' => array(
+      'info' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['cache_block'] = drupal_get_schema_unprocessed('system', 'cache');
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/blogapi/blogapi.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/blogapi/blogapi.install,v
retrieving revision 1.4
diff -u -p -r1.4 blogapi.install
--- modules/blogapi/blogapi.install	15 Nov 2008 13:01:04 -0000	1.4
+++ modules/blogapi/blogapi.install	19 Nov 2008 19:08:19 -0000
@@ -40,8 +40,7 @@ function blogapi_schema() {
         'description' => 'Path of the file relative to Drupal root.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'filesize' => array(
         'description' => 'The size of the file in bytes.',
@@ -93,3 +92,39 @@ function blogapi_update_6001() {
  * @} End of "defgroup updates-5.x-to-6.x"
  * The next series of updates should start at 7000.
  */
+
+/**
+ * @defgroup updates-6.x-to-7.x Blog API updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function blogapi_update_7000() {
+  $ret = array();
+
+  $schema['blogapi_files'] = array(
+    'fields' => array(
+      'filepath' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/comment/comment.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/comment/comment.install,v
retrieving revision 1.27
diff -u -p -r1.27 comment.install
--- modules/comment/comment.install	15 Nov 2008 13:01:05 -0000	1.27
+++ modules/comment/comment.install	19 Nov 2008 19:08:19 -0000
@@ -109,6 +109,47 @@ function comment_update_7001() {
 }
 
 /**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function comment_update_7002() {
+  $ret = array();
+
+  $schema['comments'] = array(
+    'fields' => array(
+      'subject' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'comment' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+      'hostname' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'thread' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
  * @} End of "defgroup updates-6.x-to-7.x"
  * The next series of updates should start at 8000.
  */
@@ -146,21 +187,19 @@ function comment_schema() {
       'subject' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'The comment title.',
       ),
       'comment' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
         'description' => 'The comment body.',
       ),
       'hostname' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => "The author's host name.",
       ),
       'timestamp' => array(
@@ -187,7 +226,7 @@ function comment_schema() {
       'thread' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => "The vancode representation of the comment's place in a thread.",
       ),
       'name' => array(
Index: modules/contact/contact.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/contact/contact.install,v
retrieving revision 1.11
diff -u -p -r1.11 contact.install
--- modules/contact/contact.install	15 Nov 2008 13:01:05 -0000	1.11
+++ modules/contact/contact.install	19 Nov 2008 19:08:19 -0000
@@ -37,19 +37,18 @@ function contact_schema() {
       'category' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Category name.',
       ),
       'recipients' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
         'description' => 'Comma-separated list of recipient e-mail addresses.',
       ),
       'reply' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
         'description' => 'Text of the auto-reply message.',
       ),
@@ -79,3 +78,49 @@ function contact_schema() {
 
   return $schema;
 }
+
+/**
+ * @defgroup updates-6.x-to-7.x Contact updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function contact_update_7000() {
+  $ret = array();
+
+  $schema['contact'] = array(
+    'fields' => array(
+      'category' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'recipients' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+      'reply' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/dblog/dblog.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/dblog/dblog.install,v
retrieving revision 1.10
diff -u -p -r1.10 dblog.install
--- modules/dblog/dblog.install	15 Nov 2008 13:01:05 -0000	1.10
+++ modules/dblog/dblog.install	19 Nov 2008 19:08:19 -0000
@@ -38,19 +38,18 @@ function dblog_schema() {
       'type' => array(
         'type' => 'varchar',
         'length' => 16,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Type of log message, for example "user" or "page not found."',
       ),
       'message' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
         'description' => 'Text of log message to be passed into the t() function.',
       ),
       'variables' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
         'description' => 'Serialized array of variables that match the message string and that is passed into the t() function.',
       ),
@@ -66,26 +65,23 @@ function dblog_schema() {
         'type' => 'varchar',
         'length' => 255,
         'not null' => FALSE,
-        'default' => '',
         'description' => 'Link to view the result of the event.',
       ),
       'location'  => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => 'URL of the origin of the event.',
       ),
       'referer' => array(
         'type' => 'varchar',
         'length' => 128,
         'not null' => FALSE,
-        'default' => '',
         'description' => 'URL of referring page.',
       ),
       'hostname' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Hostname of the user who triggered the event.',
       ),
       'timestamp' => array(
@@ -106,6 +102,11 @@ function dblog_schema() {
 }
 
 /**
+ * @defgroup updates-6.x-to-7.x Database logging updates from 6.x to 7.x
+ * @{
+ */
+
+/**
  * Allow NULL values for links.
  */
 function dblog_update_7001() {
@@ -123,3 +124,63 @@ function dblog_update_7002() {
   db_add_index($ret, 'watchdog', 'uid', array('uid'));
   return $ret;
 }
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function dblog_update_7003() {
+  $ret = array();
+
+  $schema['watchdog'] = array(
+    'fields' => array(
+      'type' => array(
+        'type' => 'varchar',
+        'length' => 16,
+        'not null' => FALSE,
+      ),
+      'message' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+      'variables' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+      'link' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'referer' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'location'  => array(
+        'type' => 'text',
+        'not null' => FALSE,
+      ),
+      'hostname' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/filter/filter.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/filter/filter.install,v
retrieving revision 1.10
diff -u -p -r1.10 filter.install
--- modules/filter/filter.install	15 Nov 2008 13:01:06 -0000	1.10
+++ modules/filter/filter.install	19 Nov 2008 19:08:19 -0000
@@ -22,8 +22,7 @@ function filter_schema() {
       'module' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'The origin module of the filter.',
       ),
       'delta' => array(
@@ -60,15 +59,13 @@ function filter_schema() {
       'name' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Name of the input format (Filtered HTML).',
       ),
       'roles' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'A comma-separated string of roles; references {role}.rid.', // This is bad since you can't use joins, nor index.
       ),
       'cache' => array(
@@ -99,6 +96,11 @@ function filter_schema() {
 }
 
 /**
+ * @defgroup updates-6.x-to-7.x Filter updates from 6.x to 7.x
+ * @{
+ */
+
+/**
  * Add a weight column to the filter formats table.
  */
 function filter_update_7000() {
@@ -122,3 +124,51 @@ function filter_update_7001() {
   }
   return $ret;
 }
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function filter_update_7002() {
+  $ret = array();
+
+  $schema['filters'] = array(
+    'fields' => array(
+      'module' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['filter_formats'] = array(
+    'fields' => array(
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'roles' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['cache_filter'] = drupal_get_schema_unprocessed('system', 'cache');
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/locale/locale.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/locale/locale.install,v
retrieving revision 1.31
diff -u -p -r1.31 locale.install
--- modules/locale/locale.install	15 Nov 2008 13:01:07 -0000	1.31
+++ modules/locale/locale.install	19 Nov 2008 19:08:19 -0000
@@ -12,7 +12,7 @@ function locale_install() {
   // Create tables.
   drupal_install_schema('locale');
 
-  db_query("INSERT INTO {languages} (language, name, native, direction, enabled, weight, javascript) VALUES ('en', 'English', 'English', '0', '1', '0', '')");
+  db_query("INSERT INTO {languages} (language, name, native, direction, enabled, weight, javascript) VALUES ('en', 'English', 'English', '0', '1', '0', NULL)");
 }
 
 /**
@@ -206,6 +206,130 @@ function locale_update_6005() {
  */
 
 /**
+ * @defgroup updates-6.x-to-7.x Locale updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace default language from '' to 'default'.
+ */
+function locale_update_7000() {
+  $ret = array();
+
+  $schema['languages'] = array(
+    'fields' => array(
+      'language' => array(
+        'type' => 'varchar',
+        'length' => 12,
+        'not null' => TRUE,
+        'default' => 'default',
+      ),
+    ),
+  );
+
+  $schema['locales_target'] = array(
+    'fields' => array(
+      'language' => array(
+        'type' => 'varchar',
+        'length' => 12,
+        'not null' => TRUE,
+        'default' => 'default',
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = 'default' WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function locale_update_7001() {
+  $ret = array();
+
+  $schema['languages'] = array(
+    'fields' => array(
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'native' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'formula' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'domain' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'prefix' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'javascript' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['locales_source'] = array(
+    'fields' => array(
+      'location' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'source' => array(
+        'type' => 'text',
+        'mysql_type' => 'blob',
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['locales_target'] = array(
+    'fields' => array(
+      'translation' => array(
+        'type' => 'text',
+        'mysql_type' => 'blob',
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
+
+/**
  * Implementation of hook_uninstall().
  */
 function locale_uninstall() {
@@ -232,21 +356,19 @@ function locale_schema() {
         'type' => 'varchar',
         'length' => 12,
         'not null' => TRUE,
-        'default' => '',
+        'default' => 'default',
         'description' => "Language code, e.g. 'de' or 'en-US'.",
       ),
       'name' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Language name in English.',
       ),
       'native' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Native language name.',
       ),
       'direction' => array(
@@ -270,22 +392,19 @@ function locale_schema() {
       'formula' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Plural formula in PHP code to evaluate to get plural indexes.',
       ),
       'domain' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Domain to use for this language.',
       ),
       'prefix' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Path prefix to use for this language.',
       ),
       'weight' => array(
@@ -297,8 +416,7 @@ function locale_schema() {
       'javascript' => array(
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Location of JavaScript translation file.',
       ),
     ),
@@ -319,8 +437,7 @@ function locale_schema() {
       'location' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Drupal path in case of online discovered translations or file path in case of imported strings.',
       ),
       'textgroup' => array(
@@ -333,7 +450,7 @@ function locale_schema() {
       'source' => array(
         'type' => 'text',
         'mysql_type' => 'blob',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => 'The original string in English.',
       ),
       'version' => array(
@@ -362,14 +479,14 @@ function locale_schema() {
       'translation' => array(
         'type' => 'text',
         'mysql_type' => 'blob',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => 'Translation string value in this language.',
       ),
       'language' => array(
         'type' => 'varchar',
         'length' => 12,
         'not null' => TRUE,
-        'default' => '',
+        'default' => 'default',
         'description' => 'Language code. References {languages}.language.',
       ),
       'plid' => array(
Index: modules/menu/menu.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/menu/menu.install,v
retrieving revision 1.14
diff -u -p -r1.14 menu.install
--- modules/menu/menu.install	15 Nov 2008 13:01:07 -0000	1.14
+++ modules/menu/menu.install	19 Nov 2008 19:08:19 -0000
@@ -33,15 +33,13 @@ function menu_schema() {
       'menu_name' => array(
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Primary Key: Unique key for menu. This is used as a block delta so length is 32.',
       ),
       'title' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Menu title; displayed at top of block.',
       ),
       'description' => array(
@@ -56,3 +54,43 @@ function menu_schema() {
   return $schema;
 }
 
+/**
+ * @defgroup updates-6.x-to-7.x Menu updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function menu_update_7000() {
+  $ret = array();
+
+  $schema['menu_custom'] = array(
+    'fields' => array(
+      'menu_name' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+      'title' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/node/node.admin.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/node/node.admin.inc,v
retrieving revision 1.29
diff -u -p -r1.29 node.admin.inc
--- modules/node/node.admin.inc	10 Nov 2008 05:22:59 -0000	1.29
+++ modules/node/node.admin.inc	19 Nov 2008 19:08:19 -0000
@@ -452,7 +452,7 @@ function node_admin_content($form_state)
 function node_admin_nodes() {
   // Enable language column if translation module is enabled
   // or if we have any node with language.
-  $multilanguage = (module_exists('translation') || db_result(db_query("SELECT COUNT(*) FROM {node} WHERE language != ''")));
+  $multilanguage = (module_exists('translation') || db_result(db_query("SELECT COUNT(*) FROM {node} WHERE language <> 'default'")));
 
   // Build the sortable table header.
   $header = array();
Index: modules/node/node.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/node/node.install,v
retrieving revision 1.8
diff -u -p -r1.8 node.install
--- modules/node/node.install	15 Nov 2008 13:01:08 -0000	1.8
+++ modules/node/node.install	19 Nov 2008 19:08:19 -0000
@@ -25,22 +25,20 @@ function node_schema() {
         'description' => 'The {node_type}.type of this node.',
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'language' => array(
         'description' => 'The {languages}.language of this node.',
         'type' => 'varchar',
         'length' => 12,
         'not null' => TRUE,
-        'default' => '',
+        'default' => 'default',
       ),
       'title' => array(
         'description' => 'The title of this node, always treated as non-markup plain text.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'uid' => array(
         'description' => 'The {users}.uid that owns this node; initially, this is the user that created it.',
@@ -143,8 +141,7 @@ function node_schema() {
         'description' => 'The realm in which the user must possess the grant ID. Each node access node can define one or more realms.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'grant_view' => array(
         'description' => 'Boolean indicating whether a user with the realm/grant pair can view this node.',
@@ -236,25 +233,24 @@ function node_schema() {
         'description' => 'The title of this version.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'body' => array(
         'description' => 'The body of this version.',
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
       ),
       'teaser' => array(
         'description' => 'The teaser of this version.',
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
       ),
       'log' => array(
         'description' => 'The log entry explaining the changes in this version.',
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
       ),
       'timestamp' => array(
@@ -284,31 +280,30 @@ function node_schema() {
         'description' => 'The machine-readable name of this type.',
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'name' => array(
         'description' => 'The human-readable name of this type.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'base' => array(
         'description' => 'The base string used to construct callbacks corresponding to this node type.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'description' => array(
         'description' => 'A brief description of this type.',
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'medium',
       ),
       'help' => array(
         'description' => 'Help information shown to the user when creating a {node} of this type.',
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'medium',
       ),
       'has_title' => array(
@@ -322,8 +317,7 @@ function node_schema() {
         'description' => 'The label displayed for the title field on the edit form.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'has_body' => array(
         'description' => 'Boolean indicating whether this type uses the {node_revisions}.body field.',
@@ -336,8 +330,7 @@ function node_schema() {
         'description' => 'The label displayed for the body field on the edit form.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'min_word_count' => array(
         'description' => 'The minimum number of words the body must contain.',
@@ -371,8 +364,7 @@ function node_schema() {
         'description' => 'The original machine-readable name of this node type. This may be different from the current type name if the locked field is 0.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
     ),
     'primary key' => array('type'),
@@ -382,7 +374,8 @@ function node_schema() {
 }
 
 /**
- * Drupal 6.x to 7.x updates
+ * @defgroup updates-6.x-to-7.x Node updates from 6.x to 7.x
+ * @{
  */
 
 /**
@@ -398,5 +391,130 @@ function node_update_7000() {
 }
 
 /**
- * End of 6.x to 7.x updates
+ * Replace default language from '' to 'default'.
+ */
+function node_update_7001() {
+  $ret = array();
+
+  $schema['node'] = array(
+    'fields' => array(
+      'language' => array(
+        'type' => 'varchar',
+        'length' => 12,
+        'not null' => TRUE,
+        'default' => 'default',
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = 'default' WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function node_update_7002() {
+  $ret = array();
+
+  $schema['node_access'] = array(
+    'fields' => array(
+      'realm' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['node_revisions'] = array(
+    'fields' => array(
+      'title' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'body' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+      'teaser' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+      'log' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+    ),
+  );
+
+  $schema['node_type'] = array(
+    'fields' => array(
+      'type' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'base' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'description' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'medium',
+      ),
+      'help' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'medium',
+      ),
+      'title_label' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'body_label' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'orig_type' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+    'primary key' => array('type'),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
  */
Index: modules/node/node.pages.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/node/node.pages.inc,v
retrieving revision 1.45
diff -u -p -r1.45 node.pages.inc
--- modules/node/node.pages.inc	13 Oct 2008 00:33:03 -0000	1.45
+++ modules/node/node.pages.inc	19 Nov 2008 19:08:19 -0000
@@ -57,7 +57,7 @@ function node_add($type) {
   // If a node type has been specified, validate its existence.
   if (isset($types[$type]) && node_access('create', $type)) {
     // Initialize settings:
-    $node = array('uid' => $user->uid, 'name' => (isset($user->name) ? $user->name : ''), 'type' => $type, 'language' => '');
+    $node = array('uid' => $user->uid, 'name' => (isset($user->name) ? $user->name : ''), 'type' => $type, 'language' => 'default');
 
     drupal_set_title(t('Create @name', array('@name' => $types[$type]->name)), PASS_THROUGH);
     $output = drupal_get_form($type . '_node_form', $node);
Index: modules/openid/openid.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/openid/openid.install,v
retrieving revision 1.4
diff -u -p -r1.4 openid.install
--- modules/openid/openid.install	15 Nov 2008 13:01:08 -0000	1.4
+++ modules/openid/openid.install	19 Nov 2008 19:08:19 -0000
@@ -32,7 +32,7 @@ function openid_schema() {
       'assoc_handle' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => 'Primary Key: Used to refer to this association in subsequent messages.',
       ),
       'assoc_type' => array(
@@ -68,3 +68,39 @@ function openid_schema() {
 
   return $schema;
 }
+
+/**
+ * @defgroup updates-6.x-to-7.x OpenID updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function openid_update_7000() {
+  $ret = array();
+
+  $schema['openid_association'] = array(
+    'fields' => array(
+      'assoc_handle' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/path/path.admin.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/path/path.admin.inc,v
retrieving revision 1.14
diff -u -p -r1.14 path.admin.inc
--- modules/path/path.admin.inc	13 Oct 2008 00:33:03 -0000	1.14
+++ modules/path/path.admin.inc	19 Nov 2008 19:08:19 -0000
@@ -15,7 +15,7 @@ function path_admin_overview($keys = NUL
   // Add the filter form above the overview table.
   $output = drupal_get_form('path_admin_filter_form', $keys);
   // Enable language column if locale is enabled or if we have any alias with language
-  $count = db_result(db_query("SELECT COUNT(*) FROM {url_alias} WHERE language != ''"));
+  $count = db_result(db_query("SELECT COUNT(*) FROM {url_alias} WHERE language <> 'default'"));
   $multilanguage = (module_exists('locale') || $count);
 
   if ($keys) {
@@ -83,7 +83,7 @@ function path_admin_edit($pid = 0) {
  * @see path_admin_form_validate()
  * @see path_admin_form_submit()
  */
-function path_admin_form(&$form_state, $edit = array('src' => '', 'dst' => '', 'language' => '', 'pid' => NULL)) {
+function path_admin_form(&$form_state, $edit = array('src' => '', 'dst' => '', 'language' => 'default', 'pid' => NULL)) {
 
   $form['#alias'] = $edit;
 
@@ -132,7 +132,7 @@ function path_admin_form_validate($form,
   $dst = $form_state['values']['dst'];
   $pid = isset($form_state['values']['pid']) ? $form_state['values']['pid'] : 0;
   // Language is only set if locale module is enabled, otherwise save for all languages.
-  $language = isset($form_state['values']['language']) ? $form_state['values']['language'] : '';
+  $language = $form_state['values']['language'];
 
   if (db_result(db_query("SELECT COUNT(dst) FROM {url_alias} WHERE pid != %d AND dst = '%s' AND language = '%s'", $pid, $dst, $language))) {
     form_set_error('dst', t('The alias %alias is already in use in this language.', array('%alias' => $dst)));
@@ -148,7 +148,7 @@ function path_admin_form_validate($form,
  */
 function path_admin_form_submit($form, &$form_state) {
   // Language is only set if locale module is enabled
-  path_set_alias($form_state['values']['src'], $form_state['values']['dst'], isset($form_state['values']['pid']) ? $form_state['values']['pid'] : 0, isset($form_state['values']['language']) ? $form_state['values']['language'] : '');
+  path_set_alias($form_state['values']['src'], $form_state['values']['dst'], isset($form_state['values']['pid']) ? $form_state['values']['pid'] : 0, $form_state['values']['language']);
 
   drupal_set_message(t('The alias has been saved.'));
   $form_state['redirect'] = 'admin/build/path';
Index: modules/path/path.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/path/path.module,v
retrieving revision 1.149
diff -u -p -r1.149 path.module
--- modules/path/path.module	12 Oct 2008 04:30:06 -0000	1.149
+++ modules/path/path.module	19 Nov 2008 19:08:19 -0000
@@ -78,7 +78,7 @@ function path_admin_delete($pid = 0) {
 /**
  * Set an aliased path for a given Drupal path, preventing duplicates.
  */
-function path_set_alias($path = NULL, $alias = NULL, $pid = NULL, $language = '') {
+function path_set_alias($path = NULL, $alias = NULL, $pid = NULL, $language = 'default') {
   $path = urldecode($path);
   $alias = urldecode($alias);
   // First we check if we deal with an existing alias and delete or modify it based on pid.
@@ -123,7 +123,7 @@ function path_set_alias($path = NULL, $a
 function path_nodeapi_validate(&$node, $arg) {
   if (user_access('create url aliases') || user_access('administer url aliases')) {
     if (isset($node->path)) {
-      $language = isset($node->language) ? $node->language : '';
+      $language = ($node->language != 'default') ? $node->language : 'default';
       $node->path = trim($node->path);
       if (db_result(db_query("SELECT COUNT(dst) FROM {url_alias} WHERE dst = '%s' AND src != '%s' AND language = '%s'", $node->path, "node/$node->nid", $language))) {
         form_set_error('path', t('The path is already in use.'));
@@ -136,7 +136,7 @@ function path_nodeapi_validate(&$node, $
  * Implementation of hook_nodeapi_load().
  */
 function path_nodeapi_load(&$node, $arg) {
-  $language = isset($node->language) ? $node->language : '';
+  $language = ($node->language != 'default') ? $node->language : 'default';
   $path = 'node/' . $node->nid;
   $alias = drupal_get_path_alias($path, $language);
   if ($path != $alias) {
@@ -149,7 +149,7 @@ function path_nodeapi_load(&$node, $arg)
  */
 function path_nodeapi_insert(&$node, $arg) {
   if (user_access('create url aliases') || user_access('administer url aliases')) {
-    $language = isset($node->language) ? $node->language : '';
+    $language = ($node->language != 'default') ? $node->language : 'default';
     // Don't try to insert if path is NULL. We may have already set
     // the alias ahead of time.
     if (isset($node->path)) {
@@ -163,7 +163,7 @@ function path_nodeapi_insert(&$node, $ar
  */
 function path_nodeapi_update(&$node, $arg) {
   if (user_access('create url aliases') || user_access('administer url aliases')) {
-    $language = isset($node->language) ? $node->language : '';
+    $language = ($node->language != 'default') ? $node->language : 'default';
     path_set_alias('node/' . $node->nid, isset($node->path) ? $node->path : NULL, isset($node->pid) ? $node->pid : NULL, $language);
   }
 }
@@ -173,7 +173,6 @@ function path_nodeapi_update(&$node, $ar
  */
 function path_nodeapi_delete(&$node, $arg) {
   if (user_access('create url aliases') || user_access('administer url aliases')) {
-    $language = isset($node->language) ? $node->language : '';
     $path = 'node/' . $node->nid;
     if (drupal_get_path_alias($path) != $path) {
       path_set_alias($path);
Index: modules/php/php.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/php/php.install,v
retrieving revision 1.2
diff -u -p -r1.2 php.install
--- modules/php/php.install	14 Apr 2008 17:48:41 -0000	1.2
+++ modules/php/php.install	19 Nov 2008 19:08:19 -0000
@@ -11,7 +11,7 @@ function php_install() {
   // reliable method to identify the format in an uninstall hook or in
   // subsequent clean installs.
   if (!$format_exists) {
-    db_query("INSERT INTO {filter_formats} (name, roles, cache) VALUES ('PHP code', '', 0)");
+    db_query("INSERT INTO {filter_formats} (name, roles, cache) VALUES ('PHP code', NULL, 0)");
     $format = db_result(db_query("SELECT MAX(format) FROM {filter_formats}"));
 
     // Enable the PHP evaluator filter.
Index: modules/poll/poll.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/poll/poll.install,v
retrieving revision 1.16
diff -u -p -r1.16 poll.install
--- modules/poll/poll.install	15 Nov 2008 13:01:08 -0000	1.16
+++ modules/poll/poll.install	19 Nov 2008 19:08:19 -0000
@@ -67,8 +67,7 @@ function poll_schema() {
       'chtext' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'The text for this choice.',
       ),
       'chvotes' => array(
@@ -116,8 +115,7 @@ function poll_schema() {
       'hostname' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'The IP address this vote is from unless the voter was logged in.',
       ),
     ),
@@ -131,3 +129,49 @@ function poll_schema() {
 
   return $schema;
 }
+
+/**
+ * @defgroup updates-6.x-to-7.x Poll updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function poll_update_7000() {
+  $ret = array();
+
+  $schema['poll_choices'] = array(
+    'fields' => array(
+      'chtext' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['poll_votes'] = array(
+    'fields' => array(
+      'hostname' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/profile/profile.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/profile/profile.install,v
retrieving revision 1.14
diff -u -p -r1.14 profile.install
--- modules/profile/profile.install	15 Nov 2008 13:01:08 -0000	1.14
+++ modules/profile/profile.install	19 Nov 2008 19:08:19 -0000
@@ -40,8 +40,7 @@ function profile_schema() {
       'name' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Internal name of the field used in the form HTML and URLs.',
       ),
       'explanation' => array(
@@ -148,3 +147,39 @@ function profile_schema() {
 
   return $schema;
 }
+
+/**
+ * @defgroup updates-6.x-to-7.x Profile updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function profile_update_7000() {
+  $ret = array();
+
+  $schema['profile_fields'] = array(
+    'fields' => array(
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/search/search.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/search/search.install,v
retrieving revision 1.19
diff -u -p -r1.19 search.install
--- modules/search/search.install	15 Nov 2008 13:01:09 -0000	1.19
+++ modules/search/search.install	19 Nov 2008 19:08:19 -0000
@@ -43,7 +43,7 @@ function search_schema() {
       ),
       'data' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
         'description' => 'List of space-separated words from the item.',
       ),
@@ -64,8 +64,7 @@ function search_schema() {
       'word' => array(
         'type' => 'varchar',
         'length' => 50,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'The {search_total}.word that is associated with the search item.',
       ),
       'sid' => array(
@@ -100,8 +99,7 @@ function search_schema() {
         'description' => 'Primary Key: Unique word in the search index.',
         'type' => 'varchar',
         'length' => 50,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'count' => array(
         'description' => "The count of the word in the index using Zipf's law to equalize the probability distribution.",
@@ -125,8 +123,7 @@ function search_schema() {
       'type' => array(
         'type' => 'varchar',
         'length' => 16,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'The {search_dataset}.type of the searchable item containing the link to the node.',
       ),
       'nid' => array(
@@ -153,6 +150,11 @@ function search_schema() {
 }
 
 /**
+ * @defgroup updates-6.x-to-7.x Search updates from 6.x to 7.x
+ * @{
+ */
+
+/**
  * Replace unique keys in 'search_dataset' and 'search_index' by primary keys.
  */
 function search_update_7000() {
@@ -166,3 +168,64 @@ function search_update_7000() {
 
   return $ret;
 }
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function search_update_7001() {
+  $ret = array();
+
+  $schema['search_dataset'] = array(
+    'fields' => array(
+      'data' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+    ),
+  );
+
+  $schema['search_index'] = array(
+    'fields' => array(
+      'word' => array(
+        'type' => 'varchar',
+        'length' => 50,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['search_total'] = array(
+    'fields' => array(
+      'word' => array(
+        'type' => 'varchar',
+        'length' => 50,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['search_node_links'] = array(
+    'fields' => array(
+      'type' => array(
+        'type' => 'varchar',
+        'length' => 16,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/simpletest/simpletest.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/simpletest.install,v
retrieving revision 1.14
diff -u -p -r1.14 simpletest.install
--- modules/simpletest/simpletest.install	15 Nov 2008 13:01:09 -0000	1.14
+++ modules/simpletest/simpletest.install	19 Nov 2008 19:08:19 -0000
@@ -148,34 +148,30 @@ function simpletest_schema() {
       'test_class' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'The name of the class that created this message.',
       ),
       'status' => array(
         'type' => 'varchar',
         'length' => 9,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Message status. Core understands pass, fail, exception.',
       ),
       'message' => array(
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'description' => 'The message itself.',
       ),
       'message_group' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'The message group this message belongs to. For example: warning, browser, user.',
       ),
       'function' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Name of the assertion function or method that created this message.',
       ),
       'line' => array(
@@ -187,8 +183,7 @@ function simpletest_schema() {
       'file' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Name of the file where the function is called.',
       ),
     ),
@@ -211,3 +206,63 @@ function simpletest_schema() {
   );
   return $schema;
 }
+
+/**
+ * @defgroup updates-6.x-to-7.x SimpleTest updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function simpletest_update_7000() {
+  $ret = array();
+
+  $schema['simpletest'] = array(
+    'fields' => array(
+      'test_class' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'status' => array(
+        'type' => 'varchar',
+        'length' => 9,
+        'not null' => FALSE,
+      ),
+      'message' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+      ),
+      'message_group' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'function' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'file' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/simpletest/tests/database_test.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/tests/database_test.install,v
retrieving revision 1.3
diff -u -p -r1.3 database_test.install
--- modules/simpletest/tests/database_test.install	8 Oct 2008 18:34:30 -0000	1.3
+++ modules/simpletest/tests/database_test.install	19 Nov 2008 19:08:19 -0000
@@ -22,8 +22,7 @@ function database_test_schema() {
         'description' => "A person's name",
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'age' => array(
         'description' => "The person's age",
@@ -57,8 +56,7 @@ function database_test_schema() {
         'description' => "A person's name",
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
        ),
       'age' => array(
         'description' => "The person's age",
@@ -71,8 +69,7 @@ function database_test_schema() {
         'description' => "The person's job",
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
     ),
     'primary key' => array('job'),
@@ -136,8 +133,7 @@ function database_test_schema() {
         'description' => 'The task to be completed.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'priority' => array(
         'description' => 'The priority of the task.',
Index: modules/simpletest/tests/taxonomy_test.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/tests/taxonomy_test.install,v
retrieving revision 1.2
diff -u -p -r1.2 taxonomy_test.install
--- modules/simpletest/tests/taxonomy_test.install	15 Nov 2008 13:01:09 -0000	1.2
+++ modules/simpletest/tests/taxonomy_test.install	19 Nov 2008 19:08:19 -0000
@@ -23,8 +23,7 @@ function taxonomy_test_schema() {
       'name' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'The name of the antonym.',
       ),
     ),
Index: modules/statistics/statistics.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/statistics/statistics.install,v
retrieving revision 1.14
diff -u -p -r1.14 statistics.install
--- modules/statistics/statistics.install	15 Nov 2008 13:01:09 -0000	1.14
+++ modules/statistics/statistics.install	19 Nov 2008 19:08:19 -0000
@@ -29,6 +29,42 @@ function statistics_update_1000() {
 }
 
 /**
+ * @defgroup updates-6.x-to-7.x Statistic updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function statistics_update_7000() {
+  $ret = array();
+
+  $schema['accesslog'] = array(
+    'fields' => array(
+      'sid' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
+
+/**
  * Implementation of hook_uninstall().
  */
 function statistics_uninstall() {
@@ -59,8 +95,7 @@ function statistics_schema() {
       'sid' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Browser session ID of user that visited page.',
       ),
       'title' => array(
Index: modules/system/system.admin.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.admin.inc,v
retrieving revision 1.104
diff -u -p -r1.104 system.admin.inc
--- modules/system/system.admin.inc	11 Nov 2008 22:39:59 -0000	1.104
+++ modules/system/system.admin.inc	19 Nov 2008 19:08:19 -0000
@@ -1772,7 +1772,7 @@ function system_status($check = FALSE) {
   }
   // MySQL import might have set the uid of the anonymous user to autoincrement
   // value. Let's try fixing it. See http://drupal.org/node/204411
-  db_query("UPDATE {users} SET uid = uid - uid WHERE name = '' AND pass = '' AND status = 0");
+  db_query("UPDATE {users} SET uid = uid - uid WHERE name = 'default' AND pass = 'default' AND status = 0");
 
   return theme('status_report', $requirements);
 }
Index: modules/system/system.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.install,v
retrieving revision 1.280
diff -u -p -r1.280 system.install
--- modules/system/system.install	15 Nov 2008 13:01:10 -0000	1.280
+++ modules/system/system.install	19 Nov 2008 19:08:19 -0000
@@ -351,15 +351,15 @@ function system_install() {
   // uid 2 which is not what we want. So we insert the first user here, the
   // anonymous user. uid is 1 here for now, but very soon it will be changed
   // to 0.
-  db_query("INSERT INTO {users} (name, mail) VALUES('%s', '%s')", '', '');
+  db_query("INSERT INTO {users} (name, pass, status) VALUES ('default', 'default', 0)");
   // We need some placeholders here as name and mail are uniques and data is
   // presumed to be a serialized array. Install will change uid 1 immediately
   // anyways. So we insert the superuser here, the uid is 2 here for now, but
   // very soon it will be changed to 1.
-  db_query("INSERT INTO {users} (name, mail, created, status, data) VALUES('%s', '%s', %d, %d, '%s')", 'placeholder-for-uid-1', 'placeholder-for-uid-1', REQUEST_TIME, 1, serialize(array()));
+  db_query("INSERT INTO {users} (name, mail, created, status, data) VALUES ('%s', '%s', %d, %d, '%s')", 'placeholder-for-uid-1', 'placeholder-for-uid-1', REQUEST_TIME, 1, serialize(array()));
   // This sets the above two users uid 0 (anonymous). We avoid an explicit 0
   // otherwise MySQL might insert the next auto_increment value.
-  db_query("UPDATE {users} SET uid = uid - uid WHERE name = '%s'", '');
+  db_query("UPDATE {users} SET uid = uid - uid WHERE name = 'default'");
   // This sets uid 1 (superuser). We skip uid 2 but that's not a big problem.
   db_query("UPDATE {users} SET uid = 1 WHERE name = '%s'", 'placeholder-for-uid-1');
 
@@ -378,15 +378,15 @@ function system_install() {
 
   db_query("INSERT INTO {variable} (name, value) VALUES ('%s', '%s')", 'theme_default', 's:7:"garland";');
   db_query("UPDATE {system} SET status = %d WHERE type = '%s' AND name = '%s'", 1, 'theme', 'garland');
-  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', '%s', %d)", 'user', 'login', 'garland', 1, 0, 'left', '', -1);
-  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', '%s', %d)", 'user', 'navigation', 'garland', 1, 0, 'left', '', -1);
-  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', '%s', %d)", 'system', 'powered-by', 'garland', 1, 10, 'footer', '', -1);
+  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', NULL, %d)", 'user', 'login', 'garland', 1, 0, 'left', -1);
+  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', NULL, %d)", 'user', 'navigation', 'garland', 1, 0, 'left', -1);
+  db_query("INSERT INTO {block} (module, delta, theme, status, weight, region, pages, cache) VALUES ('%s', '%s', '%s', %d, %d, '%s', NULL, %d)", 'system', 'powered-by', 'garland', 1, 10, 'footer', -1);
 
   db_query("INSERT INTO {node_access} (nid, gid, realm, grant_view, grant_update, grant_delete) VALUES (%d, %d, '%s', %d, %d, %d)", 0, 0, 'all', 1, 0, 0);
 
   // Add input formats.
   db_query("INSERT INTO {filter_formats} (name, roles, cache) VALUES ('%s', '%s', %d)", 'Filtered HTML', ',1,2,', 1);
-  db_query("INSERT INTO {filter_formats} (name, roles, cache) VALUES ('%s', '%s', %d)", 'Full HTML', '', 1);
+  db_query("INSERT INTO {filter_formats} (name, roles, cache) VALUES ('%s', NULL, %d)", 'Full HTML', 1);
 
   // Enable filters for each input format.
 
@@ -431,13 +431,12 @@ function system_schema() {
         'description' => 'The name of the variable.',
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'value' => array(
         'description' => 'The value of the variable.',
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
       ),
     ),
@@ -458,20 +457,18 @@ function system_schema() {
         'description' => 'The object that that action acts on (node, user, comment, system or custom types.)',
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'callback' => array(
         'description' => 'The callback function that executes when the action runs.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'parameters' => array(
         'description' => 'Parameters to be passed to the callback function.',
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
         'size' => 'big',
       ),
       'description' => array(
@@ -511,7 +508,7 @@ function system_schema() {
         'description' => "A string token generated against the current user's session id and the batch id, used to ensure that only the user who submitted the batch can effectively access it.",
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'timestamp' => array(
         'description' => 'A Unix timestamp indicating when this batch was submitted for processing. Stale batches are purged at cron time.',
@@ -544,8 +541,7 @@ function system_schema() {
         'description' => 'IP address',
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
     ),
     'indexes' => array(
@@ -561,8 +557,7 @@ function system_schema() {
         'description' => 'Primary Key: Unique cache ID.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'data' => array(
         'description' => 'A collection of data to cache.',
@@ -630,22 +625,19 @@ function system_schema() {
         'description' => 'Name of the file with no path components. This may differ from the basename of the filepath if the file is renamed to avoid overwriting an existing file.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'filepath' => array(
         'description' => 'Path of the file relative to Drupal root.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'filemime' => array(
         'description' => "The file's MIME type.",
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'filesize' => array(
         'description' => 'The size of the file in bytes.',
@@ -688,15 +680,13 @@ function system_schema() {
         'description' => 'Name of event (e.g. contact).',
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'hostname' => array(
         'description' => 'Hostname of the visitor.',
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'timestamp' => array(
         'description' => 'Timestamp of the event.',
@@ -745,25 +735,23 @@ function system_schema() {
         'description' => 'Primary Key: the Drupal path this entry describes',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'load_functions' => array(
         'description' => 'A serialized array of function names (like node_load) to be called to load an object corresponding to a part of the current path.',
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'to_arg_functions' => array(
         'description' => 'A serialized array of function names (like user_uid_optional_to_arg) to be called to replace a part of the router path with another string.',
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'access_callback' => array(
         'description' => 'The callback which determines the access to this router path. Defaults to user_access.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'access_arguments' => array(
         'description' => 'A serialized array of arguments for the access callback.',
@@ -774,8 +762,7 @@ function system_schema() {
         'description' => 'The name of the function that renders the page.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'page_arguments' => array(
         'description' => 'A serialized array of arguments for the page callback.',
@@ -799,36 +786,31 @@ function system_schema() {
         'description' => 'Only for local tasks (tabs) - the router path of the parent page (which may also be a local task).',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'tab_root' => array(
         'description' => 'Router path of the closest non-tab parent page. For pages that are not local tasks, this will be the same as the path.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'title' => array(
         'description' => 'The title for the current page, or the title for the tab if this is a local task.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'title_callback' => array(
         'description' => 'A function which will alter the title. Defaults to t()',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'title_arguments' => array(
         'description' => 'A serialized array of arguments for the title callback. If empty, the title will be used as the sole argument for the title callback.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'type' => array(
         'description' => 'Numeric representation of the type of the menu item, like MENU_LOCAL_TASK.',
@@ -840,20 +822,18 @@ function system_schema() {
         'description' => 'Name of a function used to render the block on the system administration page for this item.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'description' => array(
         'description' => 'A description of this item.',
         'type' => 'text',
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'position' => array(
         'description' => 'The position of the block (left or right) on the system administration page for this item.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'weight' => array(
         'description' => 'Weight of the element. Lighter weights are higher up, heavier weights go down.',
@@ -876,8 +856,7 @@ function system_schema() {
         'description' => "The menu name. All links with the same menu name (such as 'navigation') are part of the same menu.",
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'mlid' => array(
         'description' => 'The menu link ID (mlid) is the integer primary key.',
@@ -896,22 +875,19 @@ function system_schema() {
         'description' => 'The Drupal path or external path this link points to.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'router_path' => array(
         'description' => 'For links corresponding to a Drupal path (external = 0), this connects the link to a {menu_router}.path for joins.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'link_title' => array(
-      'description' => 'The text displayed for the link, which may be modified by a title callback stored in {menu_router}.',
+        'description' => 'The text displayed for the link, which may be modified by a title callback stored in {menu_router}.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'options' => array(
         'description' => 'A serialized array of options to be passed to the url() or l() function, such as a query string or HTML attributes.',
@@ -1060,35 +1036,31 @@ function system_schema() {
         'description' => 'The name of the function, class, or interface.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'type'   => array(
         'description' => 'Either function or class or interface.',
         'type' => 'varchar',
         'length' => 9,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'filename'   => array(
         'description' => 'Name of the file.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'module' => array(
         'description' => 'Name of the module the file belongs to.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => ''
+        'not null' => FALSE,
       ),
       'suffix' => array(
         'description' => "The part of the function name after the module, which is the hook this function implements, if any.",
         'type' => 'varchar',
         'length' => 68,
-        'not null' => TRUE,
-        'default' => ''
+        'not null' => FALSE,
       ),
       'weight' => array(
         'description' => "The order in which this module's hooks should be invoked relative to other modules. Equal-weighted modules are ordered by name.",
@@ -1110,13 +1082,13 @@ function system_schema() {
         'description' => 'Path to the file.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
       'md5'  => array(
         'description' => "Md5 hash of the file's contents when last parsed.",
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
+        'not null' => FALSE,
       ),
     ),
     'primary key' => array('filename'),
@@ -1135,15 +1107,13 @@ function system_schema() {
         'description' => "Primary key: A session ID. The value is generated by PHP's Session API.",
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'hostname' => array(
         'description' => 'The IP address that last used this session ID (sid).',
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'timestamp' => array(
         'description' => 'The Unix timestamp when this session last requested a page. Old records are purged by PHP automatically.',
@@ -1178,29 +1148,25 @@ function system_schema() {
         'description' => 'The path of the primary file for this item, relative to the Drupal root; e.g. modules/node/node.module.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'name' => array(
         'description' => 'The name of the item; e.g. node.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'type' => array(
         'description' => 'The type of the item, either module, theme, or theme_engine.',
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'owner' => array(
         'description' => "A theme's 'parent' . Can be either a theme or an engine.",
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'status' => array(
         'description' => 'Boolean indicating whether or not this item is enabled.',
@@ -1260,22 +1226,20 @@ function system_schema() {
         'description' => 'The Drupal path this alias is for; e.g. node/12.',
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'dst' => array(
         'description' => 'The alias for this path; e.g. title-of-the-story.',
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
       ),
       'language' => array(
-        'description' => 'The language this alias is for; if blank, the alias will be used for unknown languages. Each Drupal path can have an alias for each supported language.',
+        'description' => 'The language this alias is for; if \'default\', the alias will be used for unknown languages. Each Drupal path can have an alias for each supported language.',
         'type' => 'varchar',
         'length' => 12,
         'not null' => TRUE,
-        'default' => '',
+        'default' => 'default',
       ),
     ),
     'unique keys' => array(
@@ -3097,7 +3061,346 @@ function system_update_7012() {
 }
 
 /**
+ * Replace default language from '' to 'default'.
+ */
+function system_update_7013() {
+  $ret = array();
+
+  $schema['url_alias'] = array(
+    'fields' => array(
+      'language' => array(
+        'type' => 'varchar',
+        'length' => 12,
+        'not null' => TRUE,
+        'default' => 'default',
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = 'default' WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function system_update_7014() {
+  $ret = array();
+
+  $schema['variable'] = array(
+    'fields' => array(
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'value' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+    ),
+  );
+
+  $schema['actions'] = array(
+    'fields' => array(
+      'type' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+      'callback' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'parameters' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+        'size' => 'big',
+      ),
+    ),
+  );
+
+  $schema['batch'] = array(
+    'fields' => array(
+      'token' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['blocked_ips'] = array(
+    'fields' => array(
+      'ip' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['cache'] = array(
+    'fields' => array(
+      'cid' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['cache_form'] = $schema['cache'];
+  $schema['cache_page'] = $schema['cache'];
+  $schema['cache_menu'] = $schema['cache'];
+  $schema['cache_registry'] = $schema['cache'];
+
+  $schema['files'] = array(
+    'fields' => array(
+      'filename' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'filepath' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'filemime' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['flood'] = array(
+    'fields' => array(
+      'event' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'hostname' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['menu_router'] = array(
+    'fields' => array(
+      'path' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'load_functions' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+      ),
+      'to_arg_functions' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+      ),
+      'access_callback' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'page_callback' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'tab_parent' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'tab_root' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'title' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'title_callback' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'title_arguments' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'block_callback' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'position' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'description' => array(
+        'type' => 'text',
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['menu_links'] = array(
+    'fields' => array(
+     'menu_name' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+      'link_path' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'router_path' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'link_title' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['registry'] = array(
+    'fields' => array(
+      'name'   => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'type'   => array(
+        'type' => 'varchar',
+        'length' => 9,
+        'not null' => FALSE,
+      ),
+      'filename'   => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'module' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'suffix' => array(
+        'type' => 'varchar',
+        'length' => 68,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['registry_file'] = array(
+    'fields' => array(
+      'filename'   => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'md5'  => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['sessions'] = array(
+    'fields' => array(
+      'sid' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'hostname' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['system'] = array(
+    'fields' => array(
+      'filename' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'type' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'owner' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['url_alias'] = array(
+    'fields' => array(
+      'src' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'dst' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
  * @} End of "defgroup updates-6.x-to-7.x"
  * The next series of updates should start at 8000.
  */
-
Index: modules/system/system.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.module,v
retrieving revision 1.638
diff -u -p -r1.638 system.module
--- modules/system/system.module	15 Nov 2008 08:23:07 -0000	1.638
+++ modules/system/system.module	19 Nov 2008 19:08:20 -0000
@@ -1526,13 +1526,13 @@ function system_actions_manage() {
   }
 
   $row = array();
-  $instances_present = db_fetch_object(db_query("SELECT aid FROM {actions} WHERE parameters <> ''"));
+  $instances_present = db_fetch_object(db_query("SELECT aid FROM {actions} WHERE parameters <> 'default'"));
   $header = array(
     array('data' => t('Action type'), 'field' => 'type'),
     array('data' => t('Description'), 'field' => 'description'),
     array('data' => $instances_present ? t('Operations') : '', 'colspan' => '2')
   );
-  $sql = 'SELECT * FROM {actions}';
+  $sql = "SELECT * FROM {actions} WHERE parameters <> 'default'";
   $result = pager_query($sql . tablesort_sql($header), 50);
   while ($action = db_fetch_object($result)) {
     $row[] = array(
@@ -1630,7 +1630,7 @@ function system_actions_configure($form_
   if (is_numeric($action)) {
     $aid = $action;
     // Load stored parameter values from database.
-    $data = db_fetch_object(db_query("SELECT * FROM {actions} WHERE aid = '%s'", $aid));
+    $data = db_fetch_object(db_query("SELECT * FROM {actions} WHERE aid = '%s' AND parameters <> 'default'", $aid));
     $edit['actions_description'] = $data->description;
     $edit['actions_type'] = $data->type;
     $function = $data->callback;
Index: modules/taxonomy/taxonomy.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/taxonomy/taxonomy.install,v
retrieving revision 1.8
diff -u -p -r1.8 taxonomy.install
--- modules/taxonomy/taxonomy.install	15 Nov 2008 13:01:10 -0000	1.8
+++ modules/taxonomy/taxonomy.install	19 Nov 2008 19:08:20 -0000
@@ -24,8 +24,7 @@ function taxonomy_schema() {
       'name' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'The term name.',
       ),
       'description' => array(
@@ -155,8 +154,7 @@ function taxonomy_schema() {
       'name' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'The name of the synonym.',
       ),
     ),
@@ -179,8 +177,7 @@ function taxonomy_schema() {
       'name' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Name of the vocabulary.',
       ),
       'description' => array(
@@ -192,8 +189,7 @@ function taxonomy_schema() {
       'help' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Help text to display for the vocabulary.',
       ),
       'relations' => array(
@@ -239,8 +235,7 @@ function taxonomy_schema() {
       'module' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'The module which created the vocabulary.',
       ),
       'weight' => array(
@@ -270,8 +265,7 @@ function taxonomy_schema() {
       'type' => array(
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'The {node}.type of the node type for which the vocabulary may be used.',
       ),
     ),
@@ -284,3 +278,78 @@ function taxonomy_schema() {
   return $schema;
 }
 
+/**
+ * @defgroup updates-6.x-to-7.x Taxonomy updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function taxonomy_update_7000() {
+  $ret = array();
+
+  $schema['term_data'] = array(
+    'fields' => array(
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['term_synonym'] = array(
+    'fields' => array(
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['vocabulary'] = array(
+    'fields' => array(
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'help' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'module' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['vocabulary_node_types'] = array(
+    'fields' => array(
+      'type' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/trigger/trigger.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/trigger/trigger.install,v
retrieving revision 1.6
diff -u -p -r1.6 trigger.install
--- modules/trigger/trigger.install	15 Nov 2008 13:01:10 -0000	1.6
+++ modules/trigger/trigger.install	19 Nov 2008 19:08:20 -0000
@@ -30,22 +30,19 @@ function trigger_schema() {
       'hook' => array(
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Primary Key: The name of the internal Drupal hook upon which an action is firing; for example, nodeapi.',
       ),
       'op' => array(
         'type' => 'varchar',
         'length' => 32,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Primary Key: The specific operation of the hook upon which an action is firing: for example, presave.',
       ),
       'aid' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => "Primary Key: Action's {actions}.aid.",
       ),
       'weight' => array(
@@ -57,7 +54,52 @@ function trigger_schema() {
     ),
     'primary key' => array('hook', 'op', 'aid'),
   );
+
   return $schema;
 }
 
+/**
+ * @defgroup updates-6.x-to-7.x Trigger updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function trigger_update_7000() {
+  $ret = array();
+
+  $schema['trigger_assignments'] = array(
+    'fields' => array(
+      'hook' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+      'op' => array(
+        'type' => 'varchar',
+        'length' => 32,
+        'not null' => FALSE,
+      ),
+      'aid' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
 
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/update/update.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/update/update.install,v
retrieving revision 1.6
diff -u -p -r1.6 update.install
--- modules/update/update.install	15 Nov 2008 13:01:11 -0000	1.6
+++ modules/update/update.install	19 Nov 2008 19:08:20 -0000
@@ -62,3 +62,31 @@ function update_update_6000() {
   _update_remove_update_status_variables();
   return array();
 }
+
+/**
+ * @defgroup updates-6.x-to-7.x Update updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function update_update_7000() {
+  $ret = array();
+
+  $schema['cache_update'] = drupal_get_schema_unprocessed('system', 'cache');
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/upload/upload.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/upload/upload.install,v
retrieving revision 1.8
diff -u -p -r1.8 upload.install
--- modules/upload/upload.install	15 Nov 2008 13:01:11 -0000	1.8
+++ modules/upload/upload.install	19 Nov 2008 19:08:20 -0000
@@ -52,8 +52,7 @@ function upload_schema() {
       'description' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Description of the uploaded file.',
       ),
       'list' => array(
@@ -82,4 +81,38 @@ function upload_schema() {
   return $schema;
 }
 
+/**
+ * @defgroup updates-6.x-to-7.x Upload updates from 6.x to 7.x
+ * @{
+ */
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
+ */
+function upload_update_7000() {
+  $ret = array();
+
+  $schema['upload'] = array(
+    'fields' => array(
+      'description' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
 
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/user/user.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/user/user.install,v
retrieving revision 1.14
diff -u -p -r1.14 user.install
--- modules/user/user.install	15 Nov 2008 13:01:11 -0000	1.14
+++ modules/user/user.install	19 Nov 2008 19:08:20 -0000
@@ -23,15 +23,13 @@ function user_schema() {
       'authname' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Unique authentication name.',
       ),
       'module' => array(
         'type' => 'varchar',
         'length' => 128,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Module which is controlling the authentication.',
       ),
     ),
@@ -53,8 +51,7 @@ function user_schema() {
       'permission' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'A single permission granted to the role identified by rid.',
       ),
     ),
@@ -76,8 +73,7 @@ function user_schema() {
       'name' => array(
         'type' => 'varchar',
         'length' => 64,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => 'Unique role name.',
       ),
     ),
@@ -100,35 +96,32 @@ function user_schema() {
         'type' => 'varchar',
         'length' => 60,
         'not null' => TRUE,
-        'default' => '',
+        'default' => 'default',
         'description' => 'Unique user name.',
       ),
       'pass' => array(
         'type' => 'varchar',
         'length' => 128,
         'not null' => TRUE,
-        'default' => '',
+        'default' => 'default',
         'description' => "User's password (hashed).",
       ),
       'mail' => array(
         'type' => 'varchar',
         'length' => 64,
         'not null' => FALSE,
-        'default' => '',
         'description' => "User's email address.",
       ),
       'theme' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => "User's default theme.",
       ),
       'signature' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => "User's signature.",
       ),
       'created' => array(
@@ -166,21 +159,19 @@ function user_schema() {
         'type' => 'varchar',
         'length' => 12,
         'not null' => TRUE,
-        'default' => '',
+        'default' => 'default',
         'description' => "User's default language.",
       ),
       'picture' => array(
         'type' => 'varchar',
         'length' => 255,
-        'not null' => TRUE,
-        'default' => '',
+        'not null' => FALSE,
         'description' => "Path to the user's uploaded picture.",
       ),
       'init' => array(
         'type' => 'varchar',
         'length' => 64,
         'not null' => FALSE,
-        'default' => '',
         'description' => 'Email address used for initial account creation.',
       ),
       'data' => array(
@@ -230,7 +221,7 @@ function user_schema() {
 }
 
 /**
- * @defgroup user-updates-6.x-to-7.x User updates from 6.x to 7.x
+ * @defgroup updates-6.x-to-7.x User updates from 6.x to 7.x
  * @{
  */
 
@@ -292,7 +283,149 @@ function user_update_7001() {
 }
 
 /**
- * @} End of "defgroup user-updates-6.x-to-7.x"
- * The next series of updates should start at 8000.
+ * Replace default language from '' to 'default'.
+ */
+function user_update_7002() {
+  $ret = array();
+
+  $schema['users'] = array(
+    'fields' => array(
+      'language' => array(
+        'type' => 'varchar',
+        'length' => 12,
+        'not null' => TRUE,
+        'default' => 'default',
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = 'default' WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * Replace fields default value from '' to 'default'.
+ */
+function user_update_7003() {
+  $ret = array();
+
+  $schema['users'] = array(
+    'fields' => array(
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 60,
+        'not null' => TRUE,
+        'default' => 'default',
+        'description' => 'Unique user name.',
+      ),
+      'pass' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => TRUE,
+        'default' => 'default',
+        'description' => "User's password (hashed).",
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = 'default' WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * Replace not null CHAR, VARCHAR, TEXT or BLOB fields with default '' as nullable.
  */
+function user_update_7004() {
+  $ret = array();
 
+  $schema['authmap'] = array(
+    'fields' => array(
+      'authname' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+      'module' => array(
+        'type' => 'varchar',
+        'length' => 128,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['role_permission'] = array(
+    'fields' => array(
+      'permission' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['role'] = array(
+    'fields' => array(
+      'name' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  $schema['users'] = array(
+    'fields' => array(
+      'mail' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+      'theme' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'signature' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'picture' => array(
+        'type' => 'varchar',
+        'length' => 255,
+        'not null' => FALSE,
+      ),
+      'init' => array(
+        'type' => 'varchar',
+        'length' => 64,
+        'not null' => FALSE,
+      ),
+    ),
+  );
+
+  foreach ($schema as $table => $fields) {
+    foreach ($fields['fields'] as $field => $def) {
+      db_change_field($ret, $table, $field, $field, $def);
+      $ret[] = update_sql("UPDATE {" . $table . "} SET " . $field . " = NULL WHERE " . $field . " = ''");
+    }
+  }
+
+  return $ret;
+}
+
+/**
+ * @} End of "defgroup updates-6.x-to-7.x"
+ * The next series of updates should start at 8000.
+ */
Index: modules/user/user.test
===================================================================
RCS file: /cvs/drupal/drupal/modules/user/user.test,v
retrieving revision 1.19
diff -u -p -r1.19 user.test
--- modules/user/user.test	18 Nov 2008 15:06:47 -0000	1.19
+++ modules/user/user.test	19 Nov 2008 19:08:20 -0000
@@ -46,7 +46,7 @@ class UserRegistrationTestCase extends D
     $this->assertTrue(($user->created > REQUEST_TIME - 20 ), t('Correct creation time.'));
     $this->assertEqual($user->status, variable_get('user_register', 1) == 1 ? 1 : 0, t('Correct status field.'));
     $this->assertEqual($user->timezone, variable_get('date_default_timezone', NULL), t('Correct timezone field.'));
-    $this->assertEqual($user->language, '', t('Correct language field.'));
+    $this->assertEqual($user->language, 'default', t('Correct language field.'));
     $this->assertEqual($user->picture, '', t('Correct picture field.'));
     $this->assertEqual($user->init, $mail, t('Correct init field.'));