Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.1145
diff -u -p -r1.1145 common.inc
--- includes/common.inc	7 Apr 2010 17:30:43 -0000	1.1145
+++ includes/common.inc	8 Apr 2010 16:48:23 -0000
@@ -4634,8 +4634,10 @@ function drupal_system_listing($mask, $d
  *   (optional) An additional variable that is passed by reference. If more
  *   context needs to be provided to implementations, then this should be an
  *   keyed array as described above.
+ * @param $ids
+ *   (optional) ADD DESCRIPTION HERE
  */
-function drupal_alter($type, &$data, &$context1 = NULL, &$context2 = NULL) {
+function drupal_alter($type, &$data, &$context1 = NULL, &$context2 = NULL, $ids = array()) {
   // Use the advanced drupal_static() pattern, since this is called very often.
   static $drupal_static_fast;
   if (!isset($drupal_static_fast)) {
@@ -4646,11 +4648,38 @@ function drupal_alter($type, &$data, &$c
   // Some alter hooks are invoked many times per page request, so statically
   // cache the list of functions to call, and on subsequent calls, iterate
   // through them quickly.
-  if (!isset($functions[$type])) {
-    $functions[$type] = array();
+  $cache_key = empty($ids) ? $type : ($type . ':' . implode(',', $ids));
+  if (!isset($functions[$cache_key])) {
+    $functions[$cache_key] = array();
     $hook = $type . '_alter';
-    foreach (module_implements($hook) as $module) {
-      $functions[$type][] = $module . '_' . $hook;
+    $modules = module_implements($hook);
+    if (empty($ids)) {
+      foreach ($modules as $module) {
+        $functions[$cache_key][] = $module . '_' . $hook;
+      }
+    }
+    else {
+      foreach ($ids as $id) {
+        $modules = array_merge($modules, module_implements($type . '_' . $id . '_alter'));
+      }
+      // We need the modules in the correct order.
+      $modules = array_intersect(module_list(), $modules);
+      // @todo Uncomment the following when http://drupal.org/node/692950 lands.
+      // $implementations = array_fill_keys($modules, FALSE);
+      // drupal_alter('module_implements', $implementations, $hook);
+      // $modules = array_keys($implementations);
+      foreach ($modules as $module) {
+        $function = $module . '_' . $hook;
+        if (function_exists($function)) {
+          $functions[$cache_key][] = $function;
+        }
+        foreach ($ids as $id) {
+          $function = $module . '_' . $type . '_' . $id . '_alter';
+          if (function_exists($function)) {
+            $functions[$cache_key][] = $function;
+          }
+        }
+      }
     }
     // Allow the theme to alter variables after the theme system has been
     // initialized.
@@ -4664,12 +4693,18 @@ function drupal_alter($type, &$data, &$c
       foreach ($theme_keys as $theme_key) {
         $function = $theme_key . '_' . $hook;
         if (function_exists($function)) {
-          $functions[$type][] = $function;
+          $functions[$cache_key][] = $function;
+        }
+        foreach ($ids as $id) {
+          $function = $theme_key . '_' . $type . '_' . $id . '_alter';
+          if (function_exists($function)) {
+            $functions[$cache_key][] = $function;
+          }
         }
       }
     }
   }
-  foreach ($functions[$type] as $function) {
+  foreach ($functions[$cache_key] as $function) {
     $function($data, $context1, $context2);
   }
 }
Index: includes/form.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/form.inc,v
retrieving revision 1.449
diff -u -p -r1.449 form.inc
--- includes/form.inc	7 Apr 2010 04:39:59 -0000	1.449
+++ includes/form.inc	8 Apr 2010 16:48:24 -0000
@@ -761,11 +761,8 @@ function drupal_prepare_form($form_id, &
     }
   }
 
-  // Invoke hook_form_FORM_ID_alter() implementations.
-  drupal_alter('form_' . $form_id, $form, $form_state);
-
-  // Invoke hook_form_alter() implementations.
-  drupal_alter('form', $form, $form_state, $form_id);
+  // Invoke hook_form_alter() and hook_form_FORM_ID_alter() implementations.
+  drupal_alter('form', $form, $form_state, $form_id, array($form_id));
 }
 
 
Index: includes/database/select.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database/select.inc,v
retrieving revision 1.34
diff -u -p -r1.34 select.inc
--- includes/database/select.inc	17 Feb 2010 05:24:53 -0000	1.34
+++ includes/database/select.inc	8 Apr 2010 16:48:25 -0000
@@ -1069,10 +1069,8 @@ class SelectQuery extends Query implemen
 
     // Modules may alter all queries or only those having a particular tag.
     if (isset($this->alterTags)) {
-      drupal_alter('query', $query);
-      foreach ($this->alterTags as $tag => $value) {
-        drupal_alter("query_$tag", $query);
-      }
+      $null = NULL;
+      drupal_alter('query', $query, $null, $null, array_keys($this->alterTags));
     }
     return $this->prepared = TRUE;
   }
Index: modules/block/block.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/block/block.module,v
retrieving revision 1.415
diff -u -p -r1.415 block.module
--- modules/block/block.module	28 Mar 2010 11:16:29 -0000	1.415
+++ modules/block/block.module	8 Apr 2010 16:48:26 -0000
@@ -740,8 +740,8 @@ function _block_render_blocks($region_bl
 
         // Allow modules to modify the block before it is viewed, via either
         // hook_block_view_MODULE_DELTA_alter() or hook_block_view_alter().
-        drupal_alter("block_view_{$block->module}_{$block->delta}", $array, $block);
-        drupal_alter('block_view', $array, $block);
+        $null = NULL;
+        drupal_alter('block_view', $array, $block, $null, array($block->module . '_' . $block->delta));
 
         if (isset($cid)) {
           cache_set($cid, $array, 'cache_block', CACHE_TEMPORARY);