[Process] Make test AbstractProcessTest::testStartAfterATimeout useful again

Author: ymc-dabe

src/Symfony/Component/Process/Tests/AbstractProcessTest.php

@@ -724,12 +724,12 @@ public function testCheckTimeoutOnStartedProcess()
 
     public function testStartAfterATimeout()
     {
-        $process = $this->getProcess('php -r "$n = 1000; while ($n--) {echo \'\'; usleep(1000); }"');
+        $process = $this->getProcess(sprintf('php -r %s', escapeshellarg('$n = 1000; while ($n--) {echo \'\'; usleep(1000); }')));
         $process->setTimeout(0.1);
         try {
             $process->run();
-            $this->fail('An exception should have been raised.');
-        } catch (\Exception $e) {
+            $this->fail('A RuntimeException should have been raised.');
+        } catch (RuntimeException $e) {
         }
         $process->start();
         usleep(10000);