Issue #1158322 follow-up by chx: Fixed htmlspecialchars() expects parameter 1...

Issue #1158322 follow-up by chx: Fixed htmlspecialchars() expects parameter 1 to be string, array given errors in exception backtraces.

core/includes/bootstrap.inc

@@ -1673,7 +1673,7 @@ function request_uri($omit_query_string = FALSE) {
  *   A link to associate with the message.
  *
  * @see watchdog()
- * @see drupal_decode_exception()
+ * @see _drupal_decode_exception()
  */
 function watchdog_exception($type, Exception $exception, $message = NULL, $variables = array(), $severity = WATCHDOG_ERROR, $link = NULL) {
 

core/includes/update.inc

@@ -613,6 +613,7 @@ function update_do_one($module, $number, $dependency_map, &$context) {
 
       require_once DRUPAL_ROOT . '/core/includes/errors.inc';
       $variables = _drupal_decode_exception($e);
+      unset($variables['backtrace']);
       // The exception message is run through check_plain() by _drupal_decode_exception().
       $ret['#abort'] = array('success' => FALSE, 'query' => t('%type: !message in %function (line %line of %file).', $variables));
     }

core/modules/simpletest/lib/Drupal/simpletest/TestBase.php

@@ -1073,7 +1073,9 @@ protected function exceptionHandler($exception) {
       'file' => $exception->getFile(),
     ));
     // The exception message is run through check_plain() by _drupal_decode_exception().
-    $message = format_string('%type: !message in %function (line %line of %file). <pre class="backtrace">!backtrace</pre>', _drupal_decode_exception($exception) + array(
+    $decoded_exception = _drupal_decode_exception($exception);
+    unset($decoded_exception['backtrace']);
+    $message = format_string('%type: !message in %function (line %line of %file). <pre class="backtrace">!backtrace</pre>', $decoded_exception + array(
       '!backtrace' => format_backtrace($verbose_backtrace),
     ));
     $this->error($message, 'Uncaught exception', _drupal_get_last_caller($backtrace));