? modules/syndication
Index: includes/module.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/module.inc,v
retrieving revision 1.127
diff -u -p -r1.127 module.inc
--- includes/module.inc	27 Sep 2008 19:03:30 -0000	1.127
+++ includes/module.inc	11 Oct 2008 18:19:23 -0000
@@ -483,5 +483,13 @@ function module_invoke_all() {
  * Array of modules required by core.
  */
 function drupal_required_modules() {
-  return array('block', 'filter', 'node', 'system', 'user');
+  $files = drupal_system_listing('/\.info$/', 'modules', 'name', 0);
+  $required = array();
+  foreach ($files as $name => $file) {
+    $info = drupal_parse_info_file($file->filename);
+    if (!empty($info) && !empty($info['required']) && $info['required']) {
+      $required[] = $name;
+    }
+  }
+  return $required;
 }
Index: modules/block/block.info
===================================================================
RCS file: /cvs/drupal/drupal/modules/block/block.info,v
retrieving revision 1.10
diff -u -p -r1.10 block.info
--- modules/block/block.info	11 Oct 2008 15:54:13 -0000	1.10
+++ modules/block/block.info	11 Oct 2008 18:19:23 -0000
@@ -8,4 +8,4 @@ core = 7.x
 files[] = block.module
 files[] = block.admin.inc
 files[] = block.install
-hidden = TRUE
+required = TRUE
Index: modules/filter/filter.info
===================================================================
RCS file: /cvs/drupal/drupal/modules/filter/filter.info,v
retrieving revision 1.10
diff -u -p -r1.10 filter.info
--- modules/filter/filter.info	11 Oct 2008 15:54:14 -0000	1.10
+++ modules/filter/filter.info	11 Oct 2008 18:19:23 -0000
@@ -8,4 +8,4 @@ files[] = filter.module
 files[] = filter.admin.inc
 files[] = filter.pages.inc
 files[] = filter.install
-hidden = TRUE
+required = TRUE
Index: modules/node/node.info
===================================================================
RCS file: /cvs/drupal/drupal/modules/node/node.info,v
retrieving revision 1.9
diff -u -p -r1.9 node.info
--- modules/node/node.info	11 Oct 2008 15:54:14 -0000	1.9
+++ modules/node/node.info	11 Oct 2008 18:19:23 -0000
@@ -9,4 +9,4 @@ files[] = content_types.inc
 files[] = node.admin.inc
 files[] = node.pages.inc
 files[] = node.install
-hidden = TRUE
+required = TRUE
Index: modules/system/system.admin.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.admin.inc,v
retrieving revision 1.97
diff -u -p -r1.97 system.admin.inc
--- modules/system/system.admin.inc	11 Oct 2008 15:54:14 -0000	1.97
+++ modules/system/system.admin.inc	11 Oct 2008 18:19:25 -0000
@@ -616,7 +616,7 @@ function system_modules($form_state = ar
 
   // Remove hidden modules from display list.
   foreach ($files as $filename => $file) {
-    if (!empty($file->info['hidden'])) {
+    if (!empty($file->info['hidden']) || !empty($file->info['required'])) {
       unset($files[$filename]);
     }
   }
Index: modules/system/system.info
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.info,v
retrieving revision 1.10
diff -u -p -r1.10 system.info
--- modules/system/system.info	11 Oct 2008 15:54:14 -0000	1.10
+++ modules/system/system.info	11 Oct 2008 18:19:25 -0000
@@ -8,4 +8,4 @@ files[] = system.module
 files[] = system.admin.inc
 files[] = image.gd.inc
 files[] = system.install
-hidden = TRUE
+required = TRUE
Index: modules/user/user.info
===================================================================
RCS file: /cvs/drupal/drupal/modules/user/user.info,v
retrieving revision 1.9
diff -u -p -r1.9 user.info
--- modules/user/user.info	11 Oct 2008 15:54:14 -0000	1.9
+++ modules/user/user.info	11 Oct 2008 18:19:25 -0000
@@ -8,4 +8,4 @@ files[] = user.module
 files[] = user.admin.inc
 files[] = user.pages.inc
 files[] = user.install
-hidden = TRUE
+required = TRUE