Index: modules/dashboard/dashboard.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/dashboard/dashboard.module,v
retrieving revision 1.38
diff -u -p -r1.38 dashboard.module
--- modules/dashboard/dashboard.module	1 Oct 2010 15:24:18 -0000	1.38
+++ modules/dashboard/dashboard.module	2 Oct 2010 20:08:50 -0000
@@ -281,14 +281,16 @@ function dashboard_admin_blocks() {
   module_load_include('inc', 'block', 'block.admin');
 
   // Prepare the blocks for the current theme, and remove those that are
-  // currently displayed in non-dashboard regions.
+  // currently displayed in non-dashboard regions, or have the dashboard
+  // availability block setting disabled.
   // @todo This assumes the current page is being displayed using the same
   //   theme that the dashboard is displayed in.
   $blocks = block_admin_display_prepare_blocks($theme_key);
   $dashboard_regions = dashboard_region_descriptions();
   $regions_to_remove = array_diff_key(system_region_list($theme_key, REGIONS_VISIBLE), $dashboard_regions);
+  $available_blocks = variable_get('dashboard_available_blocks', array());
   foreach ($blocks as $id => $block) {
-    if (isset($regions_to_remove[$block['region']])) {
+    if (isset($regions_to_remove[$block['region']]) || empty($available_blocks[$block['module']][$block['delta']])) {
       unset($blocks[$id]);
     }
   }
@@ -356,6 +358,31 @@ function dashboard_form_block_admin_conf
       $region['#options'] = array_diff_key($region['#options'], $dashboard_regions);
     }
   }
+
+  // Provide a dashboard availability block setting. A block must have this
+  // setting enabled to allow it to be used in the dashboard.
+  $available_blocks = variable_get('dashboard_available_blocks', array());
+  $form['settings']['available_on_dashboard'] = array(
+    '#type' => 'checkbox',
+    '#title' => t('Available on dashboard'),
+    '#default_value' => !empty($available_blocks[$form['module']['#value']][$form['delta']['#value']]),
+  );
+  $form['#submit'][] = 'dashboard_form_block_admin_configure_submit';
+}
+
+/**
+ * Form submission handler for block configuration form.
+ */
+function dashboard_form_block_admin_configure_submit($form, &$form_state) {
+  // Save the dashboard availability setting.
+  $available_blocks = variable_get('dashboard_available_blocks', array());
+  if ($form_state['values']['available_on_dashboard']) {
+    $available_blocks[$form_state['values']['module']][$form_state['values']['delta']] = TRUE;
+  }
+  else {
+    unset($available_blocks[$form_state['values']['module']][$form_state['values']['delta']]);
+  }
+  variable_set('dashboard_available_blocks', $available_blocks);
 }
 
 /**
@@ -445,9 +472,11 @@ function dashboard_show_disabled() {
   // Blocks are not necessarily initialized at this point.
   $blocks = _block_rehash();
 
-  // Limit the list to disabled blocks for the current theme.
+  // Limit the list to disabled blocks for the current theme, which have the
+  // dashboard availability block setting.
+  $available_blocks = variable_get('dashboard_available_blocks', array());
   foreach ($blocks as $key => $block) {
-    if ($block['theme'] != $theme_key || (!empty($block['status']) && !empty($block['region']))) {
+    if ($block['theme'] != $theme_key || (!empty($block['status']) && !empty($block['region'])) || empty($available_blocks[$block['module']][$block['delta']])) {
       unset($blocks[$key]);
     }
   }
Index: profiles/standard/standard.install
===================================================================
RCS file: /cvs/drupal/drupal/profiles/standard/standard.install,v
retrieving revision 1.25
diff -u -p -r1.25 standard.install
--- profiles/standard/standard.install	1 Oct 2010 01:37:13 -0000	1.25
+++ profiles/standard/standard.install	2 Oct 2010 20:08:50 -0000
@@ -202,6 +202,23 @@ function standard_install() {
   }
   $query->execute();
 
+  // Set dashboard availability for our initial blocks.
+  variable_set('dashboard_available_blocks', array(
+    'comment' => array(
+      'recent' => TRUE,
+    ),
+    'node' => array(
+      'recent' => TRUE,
+    ),
+    'user' => array(
+      'new' => TRUE,
+      'online' => TRUE,
+    ),
+    'search' => array(
+      'form' => TRUE,
+    )
+  ));
+
   // Insert default pre-defined node types into the database. For a complete
   // list of available node type attributes, refer to the node type API
   // documentation at: http://api.drupal.org/api/HEAD/function/hook_node_info.