Index: includes/database.mysql-common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database.mysql-common.inc,v
retrieving revision 1.10
diff -u -F^f -r1.10 database.mysql-common.inc
--- includes/database.mysql-common.inc	4 Sep 2007 21:10:45 -0000	1.10
+++ includes/database.mysql-common.inc	6 Sep 2007 22:07:08 -0000
@@ -7,11 +7,6 @@
  */
 
 /**
- * @ingroup schemaapi
- * @{
- */
-
-/**
  * Runs a basic query in the active database.
  *
  * User-supplied arguments to the query should be passed in as separate
@@ -48,6 +43,11 @@ function db_query($query) {
 }
 
 /**
+ * @ingroup schemaapi
+ * @{
+ */
+
+/**
  * Generate SQL to create a new table from a Drupal schema definition.
  *
  * @param $name
@@ -71,16 +71,9 @@ function db_create_table_sql($name, $tab
   }
 
   // Process keys & indexes.
-  if (!empty($table['primary key'])) {
-    $sql .= " PRIMARY KEY (". _db_create_key_sql($table['primary key']) ."), \n";
-  }
-  if (!empty($table['unique keys'])) {
-    foreach ($table['unique keys'] as $key => $fields)
-      $sql .= " UNIQUE KEY $key (". _db_create_key_sql($fields) ."), \n";
-  }
-  if (!empty($table['indexes'])) {
-    foreach ($table['indexes'] as $index => $fields)
-      $sql .= " INDEX $index (". _db_create_key_sql($fields) ."), \n";
+  $keys = _db_create_keys_sql($table);
+  if (count($keys)) {
+    $sql .= implode(", \n", $keys) .", \n";
   }
 
   // Remove the last comma and space.
@@ -91,6 +84,26 @@ function db_create_table_sql($name, $tab
   return array($sql);
 }
 
+function _db_create_keys_sql($spec) {
+  $keys = array();
+
+  if (!empty($spec['primary key'])) {
+    $keys[] = 'PRIMARY KEY ('. _db_create_key_sql($spec['primary key']) .')';
+  }
+  if (!empty($spec['unique keys'])) {
+    foreach ($spec['unique keys'] as $key => $fields) {
+      $keys[] = 'UNIQUE KEY '. $key .' ('. _db_create_key_sql($fields) .')';
+    }
+  }
+  if (!empty($spec['indexes'])) {
+    foreach ($spec['indexes'] as $index => $fields) {
+      $keys[] = 'INDEX '. $index .' ('. _db_create_key_sql($fields) .')';
+    }
+  }
+
+  return $keys;
+}  
+
 function _db_create_key_sql($fields) {
   $ret = array();
   foreach ($fields as $field) {
@@ -427,14 +440,49 @@ function db_drop_index(&$ret, $table, $n
 /**
  * Change a field definition.
  *
- * IMPORTANT NOTE: On some database systems (notably PostgreSQL),
- * changing a field definition involves adding a new field and
- * dropping an old one. This means that any indices, primary keys and
- * sequences (from serial-type fields) that use the field to be
- * changed get dropped.  For database portability, you MUST drop them
- * explicitly before calling db_change_field() and then re-create them
- * afterwards.  Use db_{add,drop}_{primary_key,unique_key,index} for
- * this purpose.
+ * IMPORTANT NOTE: To maintain database portability, you have to explicitly
+ * recreate all indices and primary keys that are using the changed field.
+ *
+ * That means that you have to drop all affected keys and indexes with
+ * db_drop_{primary_key,unique_key,index}() before calling db_change_field().
+ * To recreate the keys and indices, pass the key definitions as the 
+ * optional $new_keys argument directly to db_change_field().
+ *
+ * For example, suppose you have:
+ * @code
+ * $schema['foo'] = array(
+ *   'fields' => array(
+ *     'bar' => array('type' => 'int', 'not null' => TRUE)
+ *   ),
+ *   'primary key' => array('bar')
+ * );
+ * @endcode
+ * and you want to change foo.bar to be type serial, leaving it as the
+ * primary key.  The correct sequence is:
+ * @code
+ * db_drop_primary_key($ret, 'foo');
+ * db_change_field($ret, 'foo', 'bar', 'bar', 
+ *   array('type' => 'serial', 'not null' => TRUE),
+ *   array('primary key' => array('bar')));
+ * @endcode
+ *
+ * The reasons for this are due to the different database engines:
+ *
+ * On PostgreSQL, changing a field definition involves adding a new field 
+ * and dropping an old one which* causes any indices, primary keys and 
+ * sequences (from serial-type fields) that use the changed field to be dropped.
+ *
+ * On MySQL, all type 'serial' fields must be part of at least one key
+ * or index as soon as they are created.  You cannot use
+ * db_add_{primary_key,unique_key,index}() for this purpose because
+ * the ALTER TABLE command will fail to add the column without a key
+ * or index specification.  The solution is to use the optional
+ * $new_keys argument to create the key or index at the same time as
+ * field.
+ *
+ * You could use db_add_{primary_key,unique_key,index}() in all cases
+ * unless you are converting a field to be type serial. You can use
+ * the $new_keys argument in all cases.
  *
  * @param $ret
  *   Array to which query results will be added.
@@ -446,10 +494,19 @@ function db_drop_index(&$ret, $table, $n
  *   New name for the field (set to the same as $field if you don't want to change the name).
  * @param $spec
  *   The field specification for the new field.
+ * @param $new_keys
+ *   Optional keys and indexes specification to be created on the
+ *   table along with changing the field. The format is the same as a
+ *   table specification but without the 'fields' element. 
  */
-function db_change_field(&$ret, $table, $field, $field_new, $spec) {
-  $ret[] = update_sql("ALTER TABLE {". $table ."} CHANGE $field ".
-    _db_create_field_sql($field_new, _db_process_field($spec)));
+
+function db_change_field(&$ret, $table, $field, $field_new, $spec, $new_keys = array()) {
+  $sql = 'ALTER TABLE {'. $table .'} CHANGE '. $field .
+    _db_create_field_sql($field_new, _db_process_field($spec));  
+  if (count($new_keys)) {
+    $sql .= ', ADD '.implode(', ADD ', _db_create_keys_sql($new_keys));
+  }
+  $ret[] = update_sql($sql);
 }
 
 /**
@@ -469,6 +526,10 @@ function db_update_field(&$ret, $table, 
 }
 
 /**
+ * @} End of "ingroup schemaapi".
+ */
+
+/**
  * Returns the last insert id.
  *
  * @param $table
@@ -479,7 +540,3 @@ function db_update_field(&$ret, $table, 
 function db_last_insert_id($table, $field) {
   return db_result(db_query('SELECT LAST_INSERT_ID()'));
 }
-
-/**
- * @} End of "ingroup schemaapi".
- */
Index: includes/database.pgsql.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database.pgsql.inc,v
retrieving revision 1.58
diff -u -F^f -r1.58 database.pgsql.inc
--- includes/database.pgsql.inc	4 Sep 2007 21:10:45 -0000	1.58
+++ includes/database.pgsql.inc	6 Sep 2007 22:07:09 -0000
@@ -831,14 +831,49 @@ function db_drop_index(&$ret, $table, $n
 /**
  * Change a field definition.
  *
- * IMPORTANT NOTE: On some database systems (notably PostgreSQL),
- * changing a field definition involves adding a new field and
- * dropping an old one. This means that any indices, primary keys and
- * sequences (from serial-type fields) that use the field to be
- * changed get dropped.  For database portability, you MUST drop them
- * explicitly before calling db_change_field() and then re-create them
- * afterwards.  Use db_{add,drop}_{primary_key,unique_key,index} for
- * this purpose.
+ * IMPORTANT NOTE: To maintain database portability, you have to explicitly
+ * recreate all indices and primary keys that are using the changed field.
+ *
+ * That means that you have to drop all affected keys and indexes with
+ * db_drop_{primary_key,unique_key,index}() before calling db_change_field().
+ * To recreate the keys and indices, pass the key definitions as the 
+ * optional $new_keys argument directly to db_change_field().
+ *
+ * For example, suppose you have:
+ * @code
+ * $schema['foo'] = array(
+ *   'fields' => array(
+ *     'bar' => array('type' => 'int', 'not null' => TRUE)
+ *   ),
+ *   'primary key' => array('bar')
+ * );
+ * @endcode
+ * and you want to change foo.bar to be type serial, leaving it as the
+ * primary key.  The correct sequence is:
+ * @code
+ * db_drop_primary_key($ret, 'foo');
+ * db_change_field($ret, 'foo', 'bar', 'bar', 
+ *   array('type' => 'serial', 'not null' => TRUE),
+ *   array('primary key' => array('bar')));
+ * @endcode
+ *
+ * The reasons for this are due to the different database engines:
+ *
+ * On PostgreSQL, changing a field definition involves adding a new field 
+ * and dropping an old one which* causes any indices, primary keys and 
+ * sequences (from serial-type fields) that use the changed field to be dropped.
+ *
+ * On MySQL, all type 'serial' fields must be part of at least one key
+ * or index as soon as they are created.  You cannot use
+ * db_add_{primary_key,unique_key,index}() for this purpose because
+ * the ALTER TABLE command will fail to add the column without a key
+ * or index specification.  The solution is to use the optional
+ * $new_keys argument to create the key or index at the same time as
+ * field.
+ *
+ * You could use db_add_{primary_key,unique_key,index}() in all cases
+ * unless you are converting a field to be type serial. You can use
+ * the $new_keys argument in all cases.
  *
  * @param $ret
  *   Array to which query results will be added.
@@ -850,17 +885,39 @@ function db_drop_index(&$ret, $table, $n
  *   New name for the field (set to the same as $field if you don't want to change the name).
  * @param $spec
  *   The field specification for the new field.
+ * @param $new_keys
+ *   Optional keys and indexes specification to be created on the
+ *   table along with changing the field. The format is the same as a
+ *   table specification but without the 'fields' element. 
  */
-function db_change_field(&$ret, $table, $field, $field_new, $spec) {
+function db_change_field(&$ret, $table, $field, $field_new, $spec, $new_keys = array()) {
   $ret[] = update_sql("ALTER TABLE {". $table ."} RENAME $field TO ". $field ."_old");
   $not_null = isset($spec['not null']) ? $spec['not null'] : FALSE;
   unset($spec['not null']);
+  
   db_add_field($ret, $table, "$field_new", $spec);
+  
   $ret[] = update_sql("UPDATE {". $table ."} SET $field_new = ". $field ."_old");
+  
   if ($not_null) {
     $ret[] = update_sql("ALTER TABLE {". $table ."} ALTER $field_new SET NOT NULL");
   }
+  
   db_drop_field($ret, $table, $field .'_old');
+
+  if (isset($new_keys['primary key'])) {
+    db_add_primary_key($ret, $table, $new_keys['primary key']);
+  }
+  if (isset($new_keys['unique keys'])) {
+    foreach ($new_keys['unique keys'] as $name => $fields) {
+      db_add_unique_key($ret, $table, $name, $fields);
+    }
+  }
+  if (isset($new_keys['indexes'])) {
+    foreach ($new_keys['indexes'] as $name => $fields) {
+      db_add_index($ret, $table, $name, $fields);
+    }
+  }
 }
 
 /**