diff -u b/modules/simpletest/simpletest.install b/modules/simpletest/simpletest.install
--- b/modules/simpletest/simpletest.install
+++ b/modules/simpletest/simpletest.install
@@ -168,6 +168,7 @@
  */
 function simpletest_uninstall() {
   drupal_load('module', 'simpletest');
+  simpletest_clean_environment();
 
   // Remove settings variables.
   variable_del('simpletest_httpauth_method');
@@ -176,7 +177,6 @@
   variable_del('simpletest_clear_results');
   variable_del('simpletest_verbose');
 
-  simpletest_clean_database();
   // Remove generated files.
   file_unmanaged_delete_recursive('public://simpletest');
 }
only in patch2:
unchanged:
--- a/modules/simpletest/simpletest.module
+++ b/modules/simpletest/simpletest.module
@@ -452,13 +452,15 @@ function simpletest_clean_database() {
  * Find all leftover temporary directories and remove them.
  */
 function simpletest_clean_temporary_directories() {
-  $files = scandir('public://simpletest');
   $count = 0;
-  foreach ($files as $file) {
-    $path = 'public://simpletest/' . $file;
-    if (is_dir($path) && is_numeric($file)) {
-      file_unmanaged_delete_recursive($path);
-      $count++;
+  if (is_dir('public://simpletest')) {
+    $files = scandir('public://simpletest');
+    foreach ($files as $file) {
+      $path = 'public://simpletest/' . $file;
+      if (is_dir($path) && is_numeric($file)) {
+        file_unmanaged_delete_recursive($path);
+        $count++;
+      }
     }
   }
 
only in patch2:
unchanged:
--- a/modules/system/system.api.php
+++ b/modules/system/system.api.php
@@ -3267,6 +3267,13 @@ function hook_update_last_removed() {
  * module's database tables are removed, allowing your module to query its own
  * tables during this routine.
  *
+ * When this hook is fired, your module will already be disabled, so its
+ * .module file will not be automatically included. If you need to call
+ * API functions from your .module file in this hook, use drupal_load() to make
+ * them available. (Keep this usage to a minimum, though, since some functions
+ * may not behave as expected due to the module being already disabled; e.g.,
+ * your module's hook implementations will not be automatically invoked.)
+ *
  * @see hook_install()
  * @see hook_schema()
  * @see hook_disable()