Index: includes/install.core.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/install.core.inc,v
retrieving revision 1.30
diff -u -p -r1.30 install.core.inc
--- includes/install.core.inc	14 Sep 2010 21:42:05 -0000	1.30
+++ includes/install.core.inc	19 Sep 2010 20:56:32 -0000
@@ -1615,7 +1615,18 @@ function install_check_requirements($ins
         // therefore must delete the file we just created and force the
         // administrator to log on to the server and create it manually.
         else {
-          drupal_unlink($settings_file);
+          $deleted = @drupal_unlink($settings_file);
+          // We expect deleting the file to be successful (since we just
+          // created it ourselves above), but if it fails somehow, we set a
+          // variable so we can display a one-time error message to the
+          // administrator at the bottom of the requirements list. We also try
+          // to make the file writable, to eliminate any conflicting error
+          // messages in the requirements list.
+          $exists = !$deleted;
+          if ($exists) {
+            $settings_file_ownership_error = TRUE;
+            $writable = drupal_verify_install_file($settings_file, FILE_READABLE|FILE_WRITABLE);
+          }
         }
       }
     }
@@ -1646,7 +1657,15 @@ function install_check_requirements($ins
       else {
         $requirements['settings file'] = array(
           'title'       => st('Settings file'),
-          'value'       => st('Settings file is writable.'),
+          'value'       => st('The settings file is writable.'),
+        );
+      }
+      if (!empty($settings_file_ownership_error)) {
+        $requirements['settings file ownership'] = array(
+          'title'       => st('Settings file'),
+          'value'       => st('The settings file is owned by the web server.'),
+          'severity'    => REQUIREMENT_ERROR,
+          'description' => st('The @drupal installer failed to create a settings file with proper file ownership. Log on to your web server, remove the existing %file file, and create a new one by copying the %default_file file to %file. More details about installing Drupal are available in <a href="@install_txt">INSTALL.txt</a>.', array('@drupal' => drupal_install_profile_distribution_name(), '%file' => $file, '%default_file' => $default_settings_file, '@install_txt' => base_path() . 'INSTALL.txt')),
         );
       }
     }