- Patch #16216 by nedjo: multiple block regions!

4 files changed, 368 insertions, 138 deletions

diff --git a/modules/block.module b/modules/block.module
index 5ab064d80..4c52e7a7b 100644
--- a/modules/block.module
+++ b/modules/block.module
@@ -13,8 +13,8 @@ function block_help($section) {
   switch ($section) {
     case 'admin/help#block':
       return t('
-<p>Blocks are the boxes visible in the sidebar(s) of your web site. These are usually generated automatically by modules (e.g. recent forum topics), but you can also create your own blocks.</p>
-<p>The sidebar each block appears in depends on both which theme you are using (some are left-only, some right, some both), and on the settings in block management.</p>
+<p>Blocks are the boxes visible in the sidebar(s) of your web site and other regions. These are usually generated automatically by modules (e.g. recent forum topics), but you can also create your own blocks.</p>
+<p>The region each block appears in depends on both which theme you are using (some are left-only, some right, some both, and some may offer other regions), and on the settings in block management.</p>
 <p>The block management screen lets you specify the vertical sort-order of the blocks within a sidebar. You do this by assigning a weight to each block. Lighter blocks (smaller weight) "float up" towards the top of the sidebar. Heavier ones "sink down" towards the bottom of it.</p>
 <p>A block\'s visibility depends on:</p>
 <ul>
@@ -31,8 +31,8 @@ function block_help($section) {
       return t('Controls the boxes that are displayed around the main content.');
     case 'admin/block':
       return t("
-<p>Blocks are the boxes in the left and right side bars of the web site. They are made available by modules or created manually.</p>
-<p>Only enabled blocks are shown. You can position the blocks by deciding which side of the page they will show up on (sidebar) and in which order they appear (weight).</p>
+<p>Blocks are content rendered into regions, often boxes in the left and right side bars of the web site. They are made available by modules or created manually.</p>
+<p>Only enabled blocks are shown. You can position the blocks by deciding which area of the page they will show up on (e.g., a sidebar) and in which order they appear (weight).  Highlighting on this page shows the regions where content will be rendered.</p>
 <p>If you want certain blocks to disable themselves temporarily during high server loads, check the 'Throttle' box. You can configure the auto-throttle on the <a href=\"%throttle\">throttle configuration page</a> after having enabled the throttle module.</p>
 ", array('%throttle' => url('admin/settings/throttle')));
     case 'admin/block/add':
@@ -71,6 +71,18 @@ function block_menu($may_cache) {
       'access' => user_access('administer blocks'),
       'callback' => 'block_box_add',
       'type' => MENU_LOCAL_TASK);
+    foreach (list_themes() as $key => $theme) {
+      if ($theme->status) {
+        if ($key == variable_get('theme_default', 'bluemarine')) {
+          $items[] = array('path' => 'admin/block/list/' . $key, 'title' => t('%key settings', array('%key' => $key)),
+            'access' => user_access('administer blocks'), 'type' => MENU_DEFAULT_LOCAL_TASK, 'weight' => -10);
+        }
+        else {
+          $items[] = array('path' => 'admin/block/list/' . $key, 'title' => t('%key settings', array('%key' => $key)),
+            'access' => user_access('administer blocks'), 'type' => MENU_LOCAL_TASK);
+        }
+      }
+    }
   }
 
   return $items;
@@ -112,8 +124,8 @@ function block_block($op = 'list', $delta = 0, $edit = array()) {
 function block_admin_save($edit) {
   foreach ($edit as $module => $blocks) {
     foreach ($blocks as $delta => $block) {
-      db_query("UPDATE {blocks} SET region = %d, status = %d, weight = %d, throttle = %d WHERE module = '%s' AND delta = '%s'",
-                $block['region'], $block['status'], $block['weight'], $block['throttle'], $module, $delta);
+      db_query("UPDATE {blocks} SET status = %d, weight = %d, region = '%s', throttle = %d WHERE module = '%s' AND delta = '%s' AND theme = '%s'",
+                $block['status'], $block['weight'], $block['region'], $block['throttle'], $module, $delta, $block['theme']);
     }
   }
 }
@@ -129,12 +141,18 @@ function block_admin_save($edit) {
  *   Blocks currently exported by modules, sorted by $order_by.
  */
 function _block_rehash($order_by = array('weight')) {
-  $result = db_query('SELECT * FROM {blocks} ');
+  global $theme_key;
+
+  if (empty($theme_key)) {
+    init_theme();
+  }
+
+  $result = db_query("SELECT * FROM {blocks} WHERE theme = '%s'", $theme_key);
   while ($old_block = db_fetch_object($result)) {
     $old_blocks[$old_block->module][$old_block->delta] = $old_block;
   }
 
-  db_query('DELETE FROM {blocks} ');
+  db_query("DELETE FROM {blocks} WHERE theme = '%s'", $theme_key);
 
   foreach (module_list() as $module) {
     $module_blocks = module_invoke($module, 'block', 'list');
@@ -142,6 +160,7 @@ function _block_rehash($order_by = array('weight')) {
       foreach ($module_blocks as $delta => $block) {
         $block['module'] = $module;
         $block['delta']  = $delta;
+        // If previously written to database, load values.
         if ($old_blocks[$module][$delta]) {
           $block['status'] = $old_blocks[$module][$delta]->status;
           $block['weight'] = $old_blocks[$module][$delta]->weight;
@@ -151,15 +170,19 @@ function _block_rehash($order_by = array('weight')) {
           $block['custom'] = $old_blocks[$module][$delta]->custom;
           $block['throttle'] = $old_blocks[$module][$delta]->throttle;
         }
+        // Otherwise, use any set values, or else substitute defaults.
         else {
-          $block['status'] = $block['weight'] = $block['region'] = $block['custom'] = 0;
-          $block['pages'] = '';
+          $properties = array ('status' => 0, 'weight' => 0, 'region' => 'left', 'pages' => '', 'custom' => 0);
+          foreach ($properties as $property => $default) {
+            if (!isset ($block[$property])) {
+              $block[$property] = $default;
+            }
+          }
         }
 
         // reinsert blocks into table
-        db_query("INSERT INTO {blocks} (module, delta, status, weight, region, visibility, pages, custom, throttle) VALUES ('%s', '%s', %d, %d, %d, %d, '%s', %d, %d)",
-          $block['module'], $block['delta'], $block['status'], $block['weight'], $block['region'], $block['visibility'], $block['pages'], $block['custom'], $block['throttle']);
-
+        db_query("INSERT INTO {blocks} (module, delta, theme, status, weight, region, visibility, pages, custom, throttle) VALUES ('%s', '%s', '%s', %d, %d, '%s', %d, '%s', %d, %d)",
+          $block['module'], $block['delta'], $theme_key, $block['status'], $block['weight'], $block['region'], $block['visibility'], $block['pages'], $block['custom'], $block['throttle']);
         $blocks[] = $block;
 
         // build array to sort on
@@ -178,17 +201,32 @@ function _block_rehash($order_by = array('weight')) {
  * Prepare the main block administration form.
  */
 function block_admin_display() {
+  global $theme_key, $custom_theme;
+
+  // If non-default theme configuration has been selected, set the custom theme.
+  if (arg(3)) {
+    $custom_theme = arg(3);
+    init_theme();
+  }
+
   $blocks = _block_rehash();
 
-  $header = array(t('Block'), t('Enabled'), t('Weight'), t('Sidebar'));
+  $block_regions = system_region_list($theme_key);
+
+  // Highlight regions on page, to provide visual reference.
+  foreach ($block_regions as $key => $value) {
+    drupal_set_content($key, '<div class="block-region">' . $value . '</div>');
+  }
+
+  $header = array(t('Block'), t('Enabled'), t('Weight'), t('Placement'));
   if (module_exist('throttle')) {
     $header[] = t('Throttle');
   }
   $header[] = array('data' => t('Operations'), 'colspan' => 2);
 
-  $left = array();
-  $right = array();
+  $regions = array();
   $disabled = array();
+
   foreach ($blocks as $block) {
     if ($block['module'] == 'block') {
       $delete = l(t('delete'), 'admin/block/delete/'. $block['delta']);
@@ -198,10 +236,10 @@ function block_admin_display() {
     }
 
     $row = array(array('data' => $block['info'], 'class' => 'block'),
-      form_checkbox(NULL, $block['module'] .']['. $block['delta'] .'][status', 1, $block['status']),
+      form_checkbox(NULL, $block['module'] .']['. $block['delta'] .'][status', 1, $block['status']) . form_hidden($block['module'] .']['. $block['delta'] .'][theme', $theme_key),
       form_weight(NULL, $block['module'] .']['. $block['delta'] .'][weight', $block['weight']),
-      form_radios(NULL, $block['module'] .']['. $block['delta'] .'][region', $block['region'],
-      array(t('left'), t('right'))));
+      form_select(NULL, $block['module'] .']['. $block['delta'] .'][region', isset($block['region']) ? $block['region'] : system_default_region(),
+      $block_regions));
 
     if (module_exist('throttle')) {
       $row[] = form_checkbox(NULL, $block['module'] .']['. $block['delta'] .'][throttle', 1, $block['throttle']);
@@ -209,11 +247,10 @@ function block_admin_display() {
     $row[] = l(t('configure'), 'admin/block/configure/'. $block['module'] .'/'. $block['delta']);
     $row[] = $delete;
     if ($block['status']) {
-      if ($block['region'] == 0) {
-        $left[] = $row;
-      }
-      if ($block['region'] == 1) {
-        $right[] = $row;
+      foreach ($block_regions as $key => $value) {
+        if ($block['region'] == $key) {
+          $regions[$key][] = $row;
+        }
       }
     }
     else if ($block['region'] <= 1) {
@@ -222,13 +259,13 @@ function block_admin_display() {
   }
 
   $rows = array();
-  if (count($left)) {
-    $rows[] = array(array('data' => t('Left sidebar'), 'class' => 'region', 'colspan' => (module_exist('throttle') ? 7 : 6)));
-    $rows = array_merge($rows, $left);
-  }
-  if (count($right)) {
-    $rows[] = array(array('data' => t('Right sidebar'), 'class' => 'region', 'colspan' => (module_exist('throttle') ? 7 : 6)));
-    $rows = array_merge($rows, $right);
+
+  if (count($regions)) {
+    foreach ($regions as $region => $row) {
+      $region_title = t('%region', array ('%region' => ucfirst($block_regions[$region])));
+      $rows[] = array(array('data' => $region_title, 'class' => 'region', 'colspan' => (module_exist('throttle') ? 7 : 6)));
+      $rows = array_merge($rows, $row);
+    }
   }
   if (count($disabled)) {
     $rows[] = array(array('data' => t('Disabled'), 'class' => 'region', 'colspan' => (module_exist('throttle') ? 7 : 6)));
@@ -237,7 +274,7 @@ function block_admin_display() {
   $output = theme('table', $header, $rows, array('id' => 'blocks'));
   $output .= form_submit(t('Save blocks'));
 
-  return form($output, 'post', url('admin/block'));
+  return form($output, 'post', arg(3) ? url('admin/block/list/' . $theme_key) : url('admin/block'));
 }
 
 function block_box_get($bid) {
@@ -412,39 +449,31 @@ function block_user($type, $edit, &$user, $category = NULL) {
   }
 }
 
- /**
-  * Return all blocks in the specied region for the current user. You may
-  * use this function to implement variable block regions.  The default
-  * regions are 'left', 'right' and 'all', where 'all' means both left and
-  * right.
-  *
-  * @param $region
-  *   This is a string which describes in a human readable form which region
-  *   you need.
-  *
-  * @param $regions
-  *   This is an optional array and contains map(s) from the string $region to
-  *   the numerical region value(s) in the blocks table. See default value for
-  *   examples.
-  *
-  * @return
-  *   An array of block objects, indexed with <i>module</i>_<i>delta</i>.
-  *   If you are displaying your blocks in one or two sidebars, you may check
-  *   whether this array is empty to see how many columns are going to be
-  *   displayed.
-  *
-  * @todo
-  *   Add a proper primary key (bid) to the blocks table so we don't have
-  *   to mess around with this <i>module</i>_<i>delta</i> construct.
-  *   Currently, the blocks table has no primary key defined!
-  */
-function block_list($region, $regions = array('left' => 0, 'right' => 1, 'all' => '0, 1')) {
-  global $user;
+/**
+ * Return all blocks in the specified region for the current user.
+ *
+ * @param $region
+ *   The name of a region.
+ *
+ * @return
+ *   An array of block objects, indexed with <i>module</i>_<i>delta</i>.
+ *   If you are displaying your blocks in one or two sidebars, you may check
+ *   whether this array is empty to see how many columns are going to be
+ *   displayed.
+ *
+ * @todo
+ *   Add a proper primary key (bid) to the blocks table so we don't have
+ *   to mess around with this <i>module</i>_<i>delta</i> construct.
+ *   Currently, the blocks table has no primary key defined!
+ */
+function block_list($region) {
+  global $user, $theme_key;
+
   static $blocks = array();
 
   if (!isset($blocks[$region])) {
     $blocks[$region] = array();
-    $result = db_query("SELECT * FROM {blocks} WHERE status = 1 AND region IN (%s) ORDER BY weight, module", $regions[$region]);
+    $result = db_query("SELECT * FROM {blocks} WHERE theme = '%s' AND status = 1 AND region = '%s' ORDER BY weight, module", $theme_key, $region);
     while ($block = db_fetch_array($result)) {
       // Use the user's block visibility setting, if necessary
       if ($block['custom'] != 0) {
diff --git a/modules/block/block.module b/modules/block/block.module
index 5ab064d80..4c52e7a7b 100644
--- a/modules/block/block.module
+++ b/modules/block/block.module
@@ -13,8 +13,8 @@ function block_help($section) {
   switch ($section) {
     case 'admin/help#block':
       return t('
-<p>Blocks are the boxes visible in the sidebar(s) of your web site. These are usually generated automatically by modules (e.g. recent forum topics), but you can also create your own blocks.</p>
-<p>The sidebar each block appears in depends on both which theme you are using (some are left-only, some right, some both), and on the settings in block management.</p>
+<p>Blocks are the boxes visible in the sidebar(s) of your web site and other regions. These are usually generated automatically by modules (e.g. recent forum topics), but you can also create your own blocks.</p>
+<p>The region each block appears in depends on both which theme you are using (some are left-only, some right, some both, and some may offer other regions), and on the settings in block management.</p>
 <p>The block management screen lets you specify the vertical sort-order of the blocks within a sidebar. You do this by assigning a weight to each block. Lighter blocks (smaller weight) "float up" towards the top of the sidebar. Heavier ones "sink down" towards the bottom of it.</p>
 <p>A block\'s visibility depends on:</p>
 <ul>
@@ -31,8 +31,8 @@ function block_help($section) {
       return t('Controls the boxes that are displayed around the main content.');
     case 'admin/block':
       return t("
-<p>Blocks are the boxes in the left and right side bars of the web site. They are made available by modules or created manually.</p>
-<p>Only enabled blocks are shown. You can position the blocks by deciding which side of the page they will show up on (sidebar) and in which order they appear (weight).</p>
+<p>Blocks are content rendered into regions, often boxes in the left and right side bars of the web site. They are made available by modules or created manually.</p>
+<p>Only enabled blocks are shown. You can position the blocks by deciding which area of the page they will show up on (e.g., a sidebar) and in which order they appear (weight).  Highlighting on this page shows the regions where content will be rendered.</p>
 <p>If you want certain blocks to disable themselves temporarily during high server loads, check the 'Throttle' box. You can configure the auto-throttle on the <a href=\"%throttle\">throttle configuration page</a> after having enabled the throttle module.</p>
 ", array('%throttle' => url('admin/settings/throttle')));
     case 'admin/block/add':
@@ -71,6 +71,18 @@ function block_menu($may_cache) {
       'access' => user_access('administer blocks'),
       'callback' => 'block_box_add',
       'type' => MENU_LOCAL_TASK);
+    foreach (list_themes() as $key => $theme) {
+      if ($theme->status) {
+        if ($key == variable_get('theme_default', 'bluemarine')) {
+          $items[] = array('path' => 'admin/block/list/' . $key, 'title' => t('%key settings', array('%key' => $key)),
+            'access' => user_access('administer blocks'), 'type' => MENU_DEFAULT_LOCAL_TASK, 'weight' => -10);
+        }
+        else {
+          $items[] = array('path' => 'admin/block/list/' . $key, 'title' => t('%key settings', array('%key' => $key)),
+            'access' => user_access('administer blocks'), 'type' => MENU_LOCAL_TASK);
+        }
+      }
+    }
   }
 
   return $items;
@@ -112,8 +124,8 @@ function block_block($op = 'list', $delta = 0, $edit = array()) {
 function block_admin_save($edit) {
   foreach ($edit as $module => $blocks) {
     foreach ($blocks as $delta => $block) {
-      db_query("UPDATE {blocks} SET region = %d, status = %d, weight = %d, throttle = %d WHERE module = '%s' AND delta = '%s'",
-                $block['region'], $block['status'], $block['weight'], $block['throttle'], $module, $delta);
+      db_query("UPDATE {blocks} SET status = %d, weight = %d, region = '%s', throttle = %d WHERE module = '%s' AND delta = '%s' AND theme = '%s'",
+                $block['status'], $block['weight'], $block['region'], $block['throttle'], $module, $delta, $block['theme']);
     }
   }
 }
@@ -129,12 +141,18 @@ function block_admin_save($edit) {
  *   Blocks currently exported by modules, sorted by $order_by.
  */
 function _block_rehash($order_by = array('weight')) {
-  $result = db_query('SELECT * FROM {blocks} ');
+  global $theme_key;
+
+  if (empty($theme_key)) {
+    init_theme();
+  }
+
+  $result = db_query("SELECT * FROM {blocks} WHERE theme = '%s'", $theme_key);
   while ($old_block = db_fetch_object($result)) {
     $old_blocks[$old_block->module][$old_block->delta] = $old_block;
   }
 
-  db_query('DELETE FROM {blocks} ');
+  db_query("DELETE FROM {blocks} WHERE theme = '%s'", $theme_key);
 
   foreach (module_list() as $module) {
     $module_blocks = module_invoke($module, 'block', 'list');
@@ -142,6 +160,7 @@ function _block_rehash($order_by = array('weight')) {
       foreach ($module_blocks as $delta => $block) {
         $block['module'] = $module;
         $block['delta']  = $delta;
+        // If previously written to database, load values.
         if ($old_blocks[$module][$delta]) {
           $block['status'] = $old_blocks[$module][$delta]->status;
           $block['weight'] = $old_blocks[$module][$delta]->weight;
@@ -151,15 +170,19 @@ function _block_rehash($order_by = array('weight')) {
           $block['custom'] = $old_blocks[$module][$delta]->custom;
           $block['throttle'] = $old_blocks[$module][$delta]->throttle;
         }
+        // Otherwise, use any set values, or else substitute defaults.
         else {
-          $block['status'] = $block['weight'] = $block['region'] = $block['custom'] = 0;
-          $block['pages'] = '';
+          $properties = array ('status' => 0, 'weight' => 0, 'region' => 'left', 'pages' => '', 'custom' => 0);
+          foreach ($properties as $property => $default) {
+            if (!isset ($block[$property])) {
+              $block[$property] = $default;
+            }
+          }
         }
 
         // reinsert blocks into table
-        db_query("INSERT INTO {blocks} (module, delta, status, weight, region, visibility, pages, custom, throttle) VALUES ('%s', '%s', %d, %d, %d, %d, '%s', %d, %d)",
-          $block['module'], $block['delta'], $block['status'], $block['weight'], $block['region'], $block['visibility'], $block['pages'], $block['custom'], $block['throttle']);
-
+        db_query("INSERT INTO {blocks} (module, delta, theme, status, weight, region, visibility, pages, custom, throttle) VALUES ('%s', '%s', '%s', %d, %d, '%s', %d, '%s', %d, %d)",
+          $block['module'], $block['delta'], $theme_key, $block['status'], $block['weight'], $block['region'], $block['visibility'], $block['pages'], $block['custom'], $block['throttle']);
         $blocks[] = $block;
 
         // build array to sort on
@@ -178,17 +201,32 @@ function _block_rehash($order_by = array('weight')) {
  * Prepare the main block administration form.
  */
 function block_admin_display() {
+  global $theme_key, $custom_theme;
+
+  // If non-default theme configuration has been selected, set the custom theme.
+  if (arg(3)) {
+    $custom_theme = arg(3);
+    init_theme();
+  }
+
   $blocks = _block_rehash();
 
-  $header = array(t('Block'), t('Enabled'), t('Weight'), t('Sidebar'));
+  $block_regions = system_region_list($theme_key);
+
+  // Highlight regions on page, to provide visual reference.
+  foreach ($block_regions as $key => $value) {
+    drupal_set_content($key, '<div class="block-region">' . $value . '</div>');
+  }
+
+  $header = array(t('Block'), t('Enabled'), t('Weight'), t('Placement'));
   if (module_exist('throttle')) {
     $header[] = t('Throttle');
   }
   $header[] = array('data' => t('Operations'), 'colspan' => 2);
 
-  $left = array();
-  $right = array();
+  $regions = array();
   $disabled = array();
+
   foreach ($blocks as $block) {
     if ($block['module'] == 'block') {
       $delete = l(t('delete'), 'admin/block/delete/'. $block['delta']);
@@ -198,10 +236,10 @@ function block_admin_display() {
     }
 
     $row = array(array('data' => $block['info'], 'class' => 'block'),
-      form_checkbox(NULL, $block['module'] .']['. $block['delta'] .'][status', 1, $block['status']),
+      form_checkbox(NULL, $block['module'] .']['. $block['delta'] .'][status', 1, $block['status']) . form_hidden($block['module'] .']['. $block['delta'] .'][theme', $theme_key),
       form_weight(NULL, $block['module'] .']['. $block['delta'] .'][weight', $block['weight']),
-      form_radios(NULL, $block['module'] .']['. $block['delta'] .'][region', $block['region'],
-      array(t('left'), t('right'))));
+      form_select(NULL, $block['module'] .']['. $block['delta'] .'][region', isset($block['region']) ? $block['region'] : system_default_region(),
+      $block_regions));
 
     if (module_exist('throttle')) {
       $row[] = form_checkbox(NULL, $block['module'] .']['. $block['delta'] .'][throttle', 1, $block['throttle']);
@@ -209,11 +247,10 @@ function block_admin_display() {
     $row[] = l(t('configure'), 'admin/block/configure/'. $block['module'] .'/'. $block['delta']);
     $row[] = $delete;
     if ($block['status']) {
-      if ($block['region'] == 0) {
-        $left[] = $row;
-      }
-      if ($block['region'] == 1) {
-        $right[] = $row;
+      foreach ($block_regions as $key => $value) {
+        if ($block['region'] == $key) {
+          $regions[$key][] = $row;
+        }
       }
     }
     else if ($block['region'] <= 1) {
@@ -222,13 +259,13 @@ function block_admin_display() {
   }
 
   $rows = array();
-  if (count($left)) {
-    $rows[] = array(array('data' => t('Left sidebar'), 'class' => 'region', 'colspan' => (module_exist('throttle') ? 7 : 6)));
-    $rows = array_merge($rows, $left);
-  }
-  if (count($right)) {
-    $rows[] = array(array('data' => t('Right sidebar'), 'class' => 'region', 'colspan' => (module_exist('throttle') ? 7 : 6)));
-    $rows = array_merge($rows, $right);
+
+  if (count($regions)) {
+    foreach ($regions as $region => $row) {
+      $region_title = t('%region', array ('%region' => ucfirst($block_regions[$region])));
+      $rows[] = array(array('data' => $region_title, 'class' => 'region', 'colspan' => (module_exist('throttle') ? 7 : 6)));
+      $rows = array_merge($rows, $row);
+    }
   }
   if (count($disabled)) {
     $rows[] = array(array('data' => t('Disabled'), 'class' => 'region', 'colspan' => (module_exist('throttle') ? 7 : 6)));
@@ -237,7 +274,7 @@ function block_admin_display() {
   $output = theme('table', $header, $rows, array('id' => 'blocks'));
   $output .= form_submit(t('Save blocks'));
 
-  return form($output, 'post', url('admin/block'));
+  return form($output, 'post', arg(3) ? url('admin/block/list/' . $theme_key) : url('admin/block'));
 }
 
 function block_box_get($bid) {
@@ -412,39 +449,31 @@ function block_user($type, $edit, &$user, $category = NULL) {
   }
 }
 
- /**
-  * Return all blocks in the specied region for the current user. You may
-  * use this function to implement variable block regions.  The default
-  * regions are 'left', 'right' and 'all', where 'all' means both left and
-  * right.
-  *
-  * @param $region
-  *   This is a string which describes in a human readable form which region
-  *   you need.
-  *
-  * @param $regions
-  *   This is an optional array and contains map(s) from the string $region to
-  *   the numerical region value(s) in the blocks table. See default value for
-  *   examples.
-  *
-  * @return
-  *   An array of block objects, indexed with <i>module</i>_<i>delta</i>.
-  *   If you are displaying your blocks in one or two sidebars, you may check
-  *   whether this array is empty to see how many columns are going to be
-  *   displayed.
-  *
-  * @todo
-  *   Add a proper primary key (bid) to the blocks table so we don't have
-  *   to mess around with this <i>module</i>_<i>delta</i> construct.
-  *   Currently, the blocks table has no primary key defined!
-  */
-function block_list($region, $regions = array('left' => 0, 'right' => 1, 'all' => '0, 1')) {
-  global $user;
+/**
+ * Return all blocks in the specified region for the current user.
+ *
+ * @param $region
+ *   The name of a region.
+ *
+ * @return
+ *   An array of block objects, indexed with <i>module</i>_<i>delta</i>.
+ *   If you are displaying your blocks in one or two sidebars, you may check
+ *   whether this array is empty to see how many columns are going to be
+ *   displayed.
+ *
+ * @todo
+ *   Add a proper primary key (bid) to the blocks table so we don't have
+ *   to mess around with this <i>module</i>_<i>delta</i> construct.
+ *   Currently, the blocks table has no primary key defined!
+ */
+function block_list($region) {
+  global $user, $theme_key;
+
   static $blocks = array();
 
   if (!isset($blocks[$region])) {
     $blocks[$region] = array();
-    $result = db_query("SELECT * FROM {blocks} WHERE status = 1 AND region IN (%s) ORDER BY weight, module", $regions[$region]);
+    $result = db_query("SELECT * FROM {blocks} WHERE theme = '%s' AND status = 1 AND region = '%s' ORDER BY weight, module", $theme_key, $region);
     while ($block = db_fetch_array($result)) {
       // Use the user's block visibility setting, if necessary
       if ($block['custom'] != 0) {
diff --git a/modules/system.module b/modules/system.module
index 214fd98fa..164732c47 100644
--- a/modules/system.module
+++ b/modules/system.module
@@ -18,7 +18,7 @@ function system_help($section) {
     case 'admin/settings':
       return t('<p>General configuration options for your site. Set up the name of the site, e-mail address used in mail-outs, clean URL options, caching, etc.</p>');
     case 'admin/themes':
-      return t('<p>Select which themes are available to your users and specify the default theme. To configure site-wide display settings, click the "configure" task above. Alternately, to override these settings in a specific theme, click the "configure" link for the corresponding theme.</p>');
+      return t('<p>Select which themes are available to your users and specify the default theme. To configure site-wide display settings, click the "configure" task above. Alternately, to override these settings in a specific theme, click the "configure" link for the corresponding theme.  Note that different themes may have different regions available for rendering content like blocks.  If you want consistency in what your users see, you may wish to enable only one theme.</p>');
     case 'admin/themes/settings':
       return t('<p>These options control the default display settings for your entire site, across all themes. Unless they have been overridden by a specific theme, these settings will be used.</p>');
     case 'admin/themes/settings/'. arg(3):
@@ -328,15 +328,21 @@ function system_theme_data() {
 
     // Add templates to the site listing
     foreach (call_user_func($engine->name . '_templates') as $template) {
-      $template->template = TRUE;
-      $template->name = basename(dirname($template->filename));
-      $template->owner = $engine->filename;
-      $template->prefix = $engine->name;
-      // do not double-insert templates with theme files in their directory
+      // Do not double-insert templates with theme files in their directory,
+      // but do register their engine data.
       if (array_key_exists($template->name, $themes)) {
-        continue;
+        $themes[$template->name]->template = TRUE;
+        $themes[$template->name]->owner = $engine->filename;
+        $themes[$template->name]->prefix = $engine->name;
+      }
+      else {
+        $template->template = TRUE;
+        $template->name = basename(dirname($template->filename));
+        $template->owner = $engine->filename;
+        $template->prefix = $engine->name;
+
+        $themes[$template->name] = $template;
       }
-      $themes[$template->name] = $template;
     }
   }
 
@@ -369,6 +375,57 @@ function system_theme_data() {
 }
 
 /**
+ * Get a list of available regions from a specified theme.
+ *
+ * @param $theme
+ *   The name of a theme.
+ * @return
+ *   An array of regions in the form $region['name'] = 'description'.
+ */
+function system_region_list($theme) {
+  static $list = array();
+
+  if(!array_key_exists($theme, $list)) {
+
+    $themes = list_themes();
+
+    if (strpos($themes[$theme]->filename, '.css')) {
+      // File is a style, which can't have its own regions; use its theme instead.
+      $theme = basename(dirname($themes[$theme]->description));
+    }
+    if (file_exists($file = dirname($themes[$theme]->filename) .'/' . $themes[$theme]->name . '.theme')) {
+      include_once($file);
+    }
+
+    $regions = function_exists($theme . '_regions') ? call_user_func($theme . '_regions') : array();
+    if (strpos($themes[$theme]->description, '.engine')) {
+      // File is a template; include its engine's regions.
+      include_once($themes[$theme]->description);
+      $theme_engine = basename($themes[$theme]->description, '.engine');
+      $engine_regions = function_exists($theme_engine . '_regions') ? call_user_func($theme_engine . '_regions') : array();
+      $regions = array_merge($engine_regions, $regions);
+    }
+
+    $list[$theme] = $regions;
+  }
+
+  return $list[$theme];
+}
+
+/**
+ * Get the name of the default region for a given theme.
+ *
+ * @param $theme
+ *   The name of a theme.
+ * @return
+ *   A string that is the region name.
+ */
+function system_default_region($theme) {
+  $regions = array_keys(system_region_list($theme));
+  return $regions[0];
+}
+
+/**
  * Returns an array of files objects of the given type from both the
  * site-wide directory (i.e. modules/) and site-specific directory
  * (i.e. sites/somesite/modules/).  The returned array will be keyed
@@ -506,6 +563,10 @@ function system_listing_save($edit = array()) {
       if (($edit['type'] == 'theme') && ($edit['theme_default'] == $name)) {
         $status = 1;
       }
+      // If status is being set to 1 from 0, initialize block data for this theme if necessary.
+      if (($status == 1) && db_num_rows(db_query("SELECT status FROM {system} WHERE type = '%s' AND name = '%s' AND status = 0", $edit['type'], $name))) {
+        system_initialize_theme_blocks($name);
+      }
 
       db_query("UPDATE {system} SET status = %d, throttle = %d WHERE type = '%s' AND name = '%s'", $status, $edit['throttle'][$name], $edit['type'], $name);
     }
@@ -520,6 +581,31 @@ function system_listing_save($edit = array()) {
     drupal_goto($_GET['q']);
   }
 }
+/**
+ * Assign an initial, default set of blocks for a theme.  This function is called the first
+ * time a new theme is enabled.  The new theme gets a copy of the default theme's blocks,
+ * with the difference that if a particular region isn't available in the new theme, the block
+ * is assigned instead to the new theme's default region.
+ *
+ * @param $theme
+ *   The name of a theme.
+ */
+function system_initialize_theme_blocks($theme) {
+  $default_theme = variable_get('theme_default', 'bluemarine');
+  $regions = system_region_list($theme);
+  // Initialize theme's blocks if none already registered.
+  if (!(db_num_rows(db_query("SELECT module FROM {blocks} WHERE theme = '%s'", $theme)))) {
+    $result = db_query("SELECT * FROM {blocks} WHERE theme = '%s'", $default_theme);
+    while($block = db_fetch_array($result)) {
+      // If the region isn't supported by the theme, assign the block to the theme's default region.
+      if (!array_key_exists($block['region'], $regions)) {
+        $block['region'] = system_default_region($theme);
+      }
+      db_query("INSERT INTO {blocks} (module, delta, theme, status, weight, region, visibility, pages, custom, throttle) VALUES ('%s', '%s', '%s', %d, %d, '%s', %d, '%s', %d, %d)",
+          $block['module'], $block['delta'], $theme, $block['status'], $block['weight'], $block['region'], $block['visibility'], $block['pages'], $block['custom'], $block['throttle']);
+    }
+  }
+}
 
 function system_settings_form($form) {
   $form .= form_submit(t('Save configuration'));
diff --git a/modules/system/system.module b/modules/system/system.module
index 214fd98fa..164732c47 100644
--- a/modules/system/system.module
+++ b/modules/system/system.module
@@ -18,7 +18,7 @@ function system_help($section) {
     case 'admin/settings':
       return t('<p>General configuration options for your site. Set up the name of the site, e-mail address used in mail-outs, clean URL options, caching, etc.</p>');
     case 'admin/themes':
-      return t('<p>Select which themes are available to your users and specify the default theme. To configure site-wide display settings, click the "configure" task above. Alternately, to override these settings in a specific theme, click the "configure" link for the corresponding theme.</p>');
+      return t('<p>Select which themes are available to your users and specify the default theme. To configure site-wide display settings, click the "configure" task above. Alternately, to override these settings in a specific theme, click the "configure" link for the corresponding theme.  Note that different themes may have different regions available for rendering content like blocks.  If you want consistency in what your users see, you may wish to enable only one theme.</p>');
     case 'admin/themes/settings':
       return t('<p>These options control the default display settings for your entire site, across all themes. Unless they have been overridden by a specific theme, these settings will be used.</p>');
     case 'admin/themes/settings/'. arg(3):
@@ -328,15 +328,21 @@ function system_theme_data() {
 
     // Add templates to the site listing
     foreach (call_user_func($engine->name . '_templates') as $template) {
-      $template->template = TRUE;
-      $template->name = basename(dirname($template->filename));
-      $template->owner = $engine->filename;
-      $template->prefix = $engine->name;
-      // do not double-insert templates with theme files in their directory
+      // Do not double-insert templates with theme files in their directory,
+      // but do register their engine data.
       if (array_key_exists($template->name, $themes)) {
-        continue;
+        $themes[$template->name]->template = TRUE;
+        $themes[$template->name]->owner = $engine->filename;
+        $themes[$template->name]->prefix = $engine->name;
+      }
+      else {
+        $template->template = TRUE;
+        $template->name = basename(dirname($template->filename));
+        $template->owner = $engine->filename;
+        $template->prefix = $engine->name;
+
+        $themes[$template->name] = $template;
       }
-      $themes[$template->name] = $template;
     }
   }
 
@@ -369,6 +375,57 @@ function system_theme_data() {
 }
 
 /**
+ * Get a list of available regions from a specified theme.
+ *
+ * @param $theme
+ *   The name of a theme.
+ * @return
+ *   An array of regions in the form $region['name'] = 'description'.
+ */
+function system_region_list($theme) {
+  static $list = array();
+
+  if(!array_key_exists($theme, $list)) {
+
+    $themes = list_themes();
+
+    if (strpos($themes[$theme]->filename, '.css')) {
+      // File is a style, which can't have its own regions; use its theme instead.
+      $theme = basename(dirname($themes[$theme]->description));
+    }
+    if (file_exists($file = dirname($themes[$theme]->filename) .'/' . $themes[$theme]->name . '.theme')) {
+      include_once($file);
+    }
+
+    $regions = function_exists($theme . '_regions') ? call_user_func($theme . '_regions') : array();
+    if (strpos($themes[$theme]->description, '.engine')) {
+      // File is a template; include its engine's regions.
+      include_once($themes[$theme]->description);
+      $theme_engine = basename($themes[$theme]->description, '.engine');
+      $engine_regions = function_exists($theme_engine . '_regions') ? call_user_func($theme_engine . '_regions') : array();
+      $regions = array_merge($engine_regions, $regions);
+    }
+
+    $list[$theme] = $regions;
+  }
+
+  return $list[$theme];
+}
+
+/**
+ * Get the name of the default region for a given theme.
+ *
+ * @param $theme
+ *   The name of a theme.
+ * @return
+ *   A string that is the region name.
+ */
+function system_default_region($theme) {
+  $regions = array_keys(system_region_list($theme));
+  return $regions[0];
+}
+
+/**
  * Returns an array of files objects of the given type from both the
  * site-wide directory (i.e. modules/) and site-specific directory
  * (i.e. sites/somesite/modules/).  The returned array will be keyed
@@ -506,6 +563,10 @@ function system_listing_save($edit = array()) {
       if (($edit['type'] == 'theme') && ($edit['theme_default'] == $name)) {
         $status = 1;
       }
+      // If status is being set to 1 from 0, initialize block data for this theme if necessary.
+      if (($status == 1) && db_num_rows(db_query("SELECT status FROM {system} WHERE type = '%s' AND name = '%s' AND status = 0", $edit['type'], $name))) {
+        system_initialize_theme_blocks($name);
+      }
 
       db_query("UPDATE {system} SET status = %d, throttle = %d WHERE type = '%s' AND name = '%s'", $status, $edit['throttle'][$name], $edit['type'], $name);
     }
@@ -520,6 +581,31 @@ function system_listing_save($edit = array()) {
     drupal_goto($_GET['q']);
   }
 }
+/**
+ * Assign an initial, default set of blocks for a theme.  This function is called the first
+ * time a new theme is enabled.  The new theme gets a copy of the default theme's blocks,
+ * with the difference that if a particular region isn't available in the new theme, the block
+ * is assigned instead to the new theme's default region.
+ *
+ * @param $theme
+ *   The name of a theme.
+ */
+function system_initialize_theme_blocks($theme) {
+  $default_theme = variable_get('theme_default', 'bluemarine');
+  $regions = system_region_list($theme);
+  // Initialize theme's blocks if none already registered.
+  if (!(db_num_rows(db_query("SELECT module FROM {blocks} WHERE theme = '%s'", $theme)))) {
+    $result = db_query("SELECT * FROM {blocks} WHERE theme = '%s'", $default_theme);
+    while($block = db_fetch_array($result)) {
+      // If the region isn't supported by the theme, assign the block to the theme's default region.
+      if (!array_key_exists($block['region'], $regions)) {
+        $block['region'] = system_default_region($theme);
+      }
+      db_query("INSERT INTO {blocks} (module, delta, theme, status, weight, region, visibility, pages, custom, throttle) VALUES ('%s', '%s', '%s', %d, %d, '%s', %d, '%s', %d, %d)",
+          $block['module'], $block['delta'], $theme, $block['status'], $block['weight'], $block['region'], $block['visibility'], $block['pages'], $block['custom'], $block['throttle']);
+    }
+  }
+}
 
 function system_settings_form($form) {
   $form .= form_submit(t('Save configuration'));