Catch unhandled exceptions in index.php

Summary:
When there is an exception in `index.php` then we currently get only blank screen.
Print it instead.

Test Plan: Thrown exceptions on several places of `index.php` and controller, got best results.

Reviewers: epriestley, btrahan

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D3619

webroot/index.php

@@ -109,18 +109,14 @@ try {
 
   PhutilErrorHandler::initialize();
 
-} catch (Exception $ex) {
+  PhutilErrorHandler::setErrorListener(
-  phabricator_fatal("[Initialization Exception] ".$ex->getMessage());
-}
-
-PhutilErrorHandler::setErrorListener(
     array('DarkConsoleErrorLogPluginAPI', 'handleErrors'));
 
-foreach (PhabricatorEnv::getEnvConfig('load-libraries') as $library) {
+  foreach (PhabricatorEnv::getEnvConfig('load-libraries') as $library) {
     phutil_load_library($library);
-}
+  }
 
-if (PhabricatorEnv::getEnvConfig('phabricator.setup')) {
+  if (PhabricatorEnv::getEnvConfig('phabricator.setup')) {
     try {
       PhabricatorSetup::runSetup();
     } catch (Exception $ex) {
@@ -128,50 +124,50 @@ if (PhabricatorEnv::getEnvConfig('phabricator.setup')) {
       echo $ex;
     }
     return;
-}
+  }
 
-phabricator_detect_bad_base_uri();
+  phabricator_detect_bad_base_uri();
 
-$translation = PhabricatorEnv::newObjectFromConfig('translation.provider');
+  $translation = PhabricatorEnv::newObjectFromConfig('translation.provider');
-PhutilTranslator::getInstance()
+  PhutilTranslator::getInstance()
     ->setLanguage($translation->getLanguage())
     ->addTranslations($translation->getTranslations());
 
-$host = $_SERVER['HTTP_HOST'];
+  $host = $_SERVER['HTTP_HOST'];
-$path = $_REQUEST['__path__'];
+  $path = $_REQUEST['__path__'];
 
-switch ($host) {
+  switch ($host) {
     default:
       $config_key = 'aphront.default-application-configuration-class';
       $application = PhabricatorEnv::newObjectFromConfig($config_key);
       break;
-}
+  }
 
 
-$application->setHost($host);
+  $application->setHost($host);
-$application->setPath($path);
+  $application->setPath($path);
-$application->willBuildRequest();
+  $application->willBuildRequest();
-$request = $application->buildRequest();
+  $request = $application->buildRequest();
 
-$write_guard = new AphrontWriteGuard(array($request, 'validateCSRF'));
+  $write_guard = new AphrontWriteGuard(array($request, 'validateCSRF'));
-PhabricatorEventEngine::initialize();
+  PhabricatorEventEngine::initialize();
 
-$application->setRequest($request);
+  $application->setRequest($request);
-list($controller, $uri_data) = $application->buildController();
+  list($controller, $uri_data) = $application->buildController();
 
-if ($access_log) {
+  if ($access_log) {
     $access_log->setData(
       array(
         'U' => (string)$request->getRequestURI()->getPath(),
         'C' => get_class($controller),
       ));
-}
+  }
 
-// If execution throws an exception and then trying to render that exception
+  // If execution throws an exception and then trying to render that exception
-// throws another exception, we want to show the original exception, as it is
+  // throws another exception, we want to show the original exception, as it is
-// likely the root cause of the rendering exception.
+  // likely the root cause of the rendering exception.
-$original_exception = null;
+  $original_exception = null;
-try {
+  try {
     $response = $controller->willBeginExecution();
 
     if ($access_log) {
@@ -187,20 +183,20 @@ try {
       $controller->willProcessRequest($uri_data);
       $response = $controller->processRequest();
     }
-} catch (AphrontRedirectException $ex) {
+  } catch (AphrontRedirectException $ex) {
     $response = id(new AphrontRedirectResponse())
       ->setURI($ex->getURI());
-} catch (Exception $ex) {
+  } catch (Exception $ex) {
     $original_exception = $ex;
     $response = $application->handleException($ex);
-}
+  }
 
-try {
+  try {
     $response = $controller->didProcessRequest($response);
     $response = $application->willSendResponse($response, $controller);
     $response->setRequest($request);
     $response_string = $response->buildResponseString();
-} catch (Exception $ex) {
+  } catch (Exception $ex) {
     $write_guard->dispose();
     if ($access_log) {
       $access_log->write();
@@ -214,32 +210,32 @@ try {
         ));
     }
     phabricator_fatal('[Rendering Exception] '.$ex->getMessage());
-}
+  }
 
-$write_guard->dispose();
+  $write_guard->dispose();
 
-// TODO: Share the $sink->writeResponse() pathway here?
+  // TODO: Share the $sink->writeResponse() pathway here?
 
-$sink = new AphrontPHPHTTPSink();
+  $sink = new AphrontPHPHTTPSink();
-$sink->writeHTTPStatus($response->getHTTPResponseCode());
+  $sink->writeHTTPStatus($response->getHTTPResponseCode());
 
-$headers = $response->getCacheHeaders();
+  $headers = $response->getCacheHeaders();
-$headers = array_merge($headers, $response->getHeaders());
+  $headers = array_merge($headers, $response->getHeaders());
 
-$sink->writeHeaders($headers);
+  $sink->writeHeaders($headers);
 
-$sink->writeData($response_string);
+  $sink->writeData($response_string);
 
-if ($access_log) {
+  if ($access_log) {
     $access_log->setData(
       array(
         'c' => $response->getHTTPResponseCode(),
         'T' => (int)(1000000 * (microtime(true) - $__start__)),
       ));
     $access_log->write();
-}
+  }
 
-if (DarkConsoleXHProfPluginAPI::isProfilerRequested()) {
+  if (DarkConsoleXHProfPluginAPI::isProfilerRequested()) {
     $profile = DarkConsoleXHProfPluginAPI::stopProfiler();
     $profile_sample = id(new PhabricatorXHProfSample())
       ->setFilePHID($profile);
@@ -257,8 +253,13 @@ if (DarkConsoleXHProfPluginAPI::isProfilerRequested()) {
         ->setUserPHID($request->getUser()->getPHID());
     }
     $profile_sample->save();
+  }
+
+} catch (Exception $ex) {
+  phabricator_fatal("[Exception] ".$ex->getMessage());
 }
 
+
 /**
  * @group aphront
  */
@@ -352,11 +353,15 @@ function phabricator_fatal($msg) {
 
   global $access_log;
   if ($access_log) {
+    try {
       $access_log->setData(
         array(
           'c' => 500,
         ));
       $access_log->write();
+    } catch (Exception $ex) {
+      $msg .= "\nMoreover unable to write to access log.";
+    }
   }
 
   header(