bug symfony#10564 fixed the profiler when an uncalled listener throws an exception when instantiated (fabpot)

This PR was merged into the 2.3 branch.

Discussion
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fixed the profiler when an uncalled listener throws an exception when instantiated

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | symfony#10371
| License       | MIT
| Doc PR        | n/a

When the profiler gets the uncalled listeners, the current page is broken without a very clear message. That happens when a listener is a service that depends for instance on the request; creating this service throws an exception.

After this patch, if we cannot get the listeners, we give up and add a log message about the problem (the error message is an info as the problem is not really related to the toolbar but more about how things work).

Commits
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79540d4 fixed the profiler when an uncalled listener throws an exception when instantiated

Author: fabpot

src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/events.html.twig

@@ -36,9 +36,9 @@
         {% endfor %}
     </table>
 
-    {% if collector.notcalledlisteners %}
-        <h2>Not Called Listeners</h2>
+    <h2>Not Called Listeners</h2>
 
+    {% if collector.notcalledlisteners %}
         <table>
             <tr>
                 <th>Event name</th>
@@ -52,6 +52,17 @@
                 </tr>
             {% endfor %}
         </table>
+    {% else %}
+        <p>
+            <strong>No uncalled listeners</strong>.
+        </p>
+        <p>
+
+            All listeners were called for this request or an error occurred
+            when trying to collect uncalled listeners (in which case check the
+            logs to get more information).
+
+        </p>
     {% endif %}
 {% endblock %}
 

src/Symfony/Component/HttpKernel/Debug/TraceableEventDispatcher.php

@@ -160,9 +160,19 @@ public function getCalledListeners()
      */
     public function getNotCalledListeners()
     {
-        $notCalled = array();
+        try {
+            $allListeners = $this->getListeners();
+        } catch (\Exception $e) {
+            if (null !== $this->logger) {
+                $this->logger->info(sprintf('An exception was thrown while getting the uncalled listeners (%s)', $e->getMessage()), array('exception' => $e));
+            }
 
-        foreach ($this->getListeners() as $name => $listeners) {
+            // unable to retrieve the uncalled listeners
+            return array();
+        }
+
+        $notCalled = array();
+        foreach ($allListeners as $name => $listeners) {
             foreach ($listeners as $listener) {
                 $info = $this->getListenerInfo($listener, null, $name);
                 if (!isset($this->called[$name.'.'.$info['pretty']])) {