bug #20519 [Debug] Remove GLOBALS from exception context to avoid endless recursion (Seldaek)

This PR was merged into the 2.7 branch.

Discussion
----------

[Debug] Remove GLOBALS from exception context to avoid endless recursion

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| License       | MIT

This fixes a endless recursion as seen in https://github.com/felixfbecker/php-language-server/pull/137 - it only happens if you trigger an error in the global context so it's kinda hard to write a test for, but hopefully the fix can be accepted.

Commits
-------

1bb95ac [Debug] Remove GLOBALS from exception context to avoid endless recursion

DebugClassLoader.php

@@ -51,15 +51,25 @@ class DebugClassLoader
         }
 
         if (!isset(self::$caseCheck)) {
-            if(!file_exists(strtolower(__FILE__))) {
+            $file = file_exists(__FILE__) ? __FILE__ : rtrim(realpath('.'), DIRECTORY_SEPARATOR);
+            $i = strrpos($file, DIRECTORY_SEPARATOR);
+            $dir = substr($file, 0, 1 + $i);
+            $file = substr($file, 1 + $i);
+            $test = strtoupper($file) === $file ? strtolower($file) : strtoupper($file);
+            $test = realpath($dir.$test);
+
+            if (false === $test || false === $i) {
                 // filesystem is case sensitive
                 self::$caseCheck = 0;
-            } elseif(realpath(strtolower(__FILE__)) === __FILE__) {
-                // filesystem is not case sensitive
+            } elseif (substr($test, -strlen($file)) === $file) {
+                // filesystem is case insensitive and realpath() normalizes the case of characters
                 self::$caseCheck = 1;
-            } else {
-                // filesystem is not case sensitive AND realpath() fails to normalize case
+            } elseif (false !== stripos(PHP_OS, 'darwin')) {
+                // on MacOSX, HFS+ is case insensitive but realpath() doesn't normalize the case of characters
                 self::$caseCheck = 2;
+            } else {
+                // filesystem case checks failed, fallback to disabling them
+                self::$caseCheck = 0;
             }
         }
     }
@@ -165,6 +175,10 @@ class DebugClassLoader
         } catch (\Exception $e) {
             ErrorHandler::unstackErrors();
 
+            throw $e;
+        } catch (\Throwable $e) {
+            ErrorHandler::unstackErrors();
+
             throw $e;
         }
 

ErrorHandler.php

@@ -349,12 +349,14 @@ class ErrorHandler
     /**
      * Handles errors by filtering then logging them according to the configured bit fields.
      *
-     * @param int    $type    One of the E_* constants
+     * @param int    $type      One of the E_* constants
+     * @param string $message
      * @param string $file
      * @param int    $line
      * @param array  $context
+     * @param array  $backtrace
      *
-     * @return bool Returns false when no handling happens so that the PHP engine can handle the error itself.
+     * @return bool Returns false when no handling happens so that the PHP engine can handle the error itself
      *
      * @throws \ErrorException When $this->thrownErrors requests so
      *
@@ -371,7 +373,7 @@ class ErrorHandler
             return $type && $log;
         }
 
-        if (PHP_VERSION_ID < 50400 && isset($context['GLOBALS']) && ($this->scopedErrors & $type)) {
+        if (isset($context['GLOBALS']) && ($this->scopedErrors & $type)) {
             $e = $context;                  // Whatever the signature of the method,
             unset($e['GLOBALS'], $context); // $context is always a reference in 5.3
             $context = $e;
@@ -447,6 +449,10 @@ class ErrorHandler
             } catch (\Exception $e) {
                 $this->isRecursive = false;
 
+                throw $e;
+            } catch (\Throwable $e) {
+                $this->isRecursive = false;
+
                 throw $e;
             }
         }
@@ -469,7 +475,7 @@ class ErrorHandler
         }
         $type = $exception instanceof FatalErrorException ? $exception->getSeverity() : E_ERROR;
 
-        if ($this->loggedErrors & $type) {
+        if (($this->loggedErrors & $type) || $exception instanceof FatalThrowableError) {
             $e = array(
                 'type' => $type,
                 'file' => $exception->getFile(),
@@ -496,9 +502,9 @@ class ErrorHandler
             } else {
                 $message = 'Uncaught Exception: '.$exception->getMessage();
             }
-            if ($this->loggedErrors & $e['type']) {
-                $this->loggers[$e['type']][0]->log($this->loggers[$e['type']][1], $message, $e);
-            }
+        }
+        if ($this->loggedErrors & $type) {
+            $this->loggers[$type][0]->log($this->loggers[$type][1], $message, $e);
         }
         if ($exception instanceof FatalErrorException && !$exception instanceof OutOfMemoryException && $error) {
             foreach ($this->getFatalErrorHandlers() as $handler) {
@@ -555,6 +561,8 @@ class ErrorHandler
             }
         } catch (\Exception $exception) {
             // Handled below
+        } catch (\Throwable $exception) {
+            // Handled below
         }
 
         if ($error && $error['type'] &= E_PARSE | E_ERROR | E_CORE_ERROR | E_COMPILE_ERROR) {

Exception/FatalThrowableError.php

@@ -27,7 +27,7 @@ class FatalThrowableError extends FatalErrorException
             $message = 'Type error: '.$e->getMessage();
             $severity = E_RECOVERABLE_ERROR;
         } else {
-            $message = 'Fatal error: '.$e->getMessage();
+            $message = $e->getMessage();
             $severity = E_ERROR;
         }
 

Exception/FlattenException.php

@@ -263,7 +263,10 @@ class FlattenException extends LegacyFlattenException
             if (++$count > 1e4) {
                 return array('array', '*SKIPPED over 10000 entries*');
             }
-            if (is_object($value)) {
+            if ($value instanceof \__PHP_Incomplete_Class) {
+                // is_object() returns false on PHP<=7.1
+                $result[$key] = array('incomplete-object', $this->getClassNameFromIncomplete($value));
+            } elseif (is_object($value)) {
                 $result[$key] = array('object', get_class($value));
             } elseif (is_array($value)) {
                 if ($level > 10) {
@@ -277,9 +280,6 @@ class FlattenException extends LegacyFlattenException
                 $result[$key] = array('boolean', $value);
             } elseif (is_resource($value)) {
                 $result[$key] = array('resource', get_resource_type($value));
-            } elseif ($value instanceof \__PHP_Incomplete_Class) {
-                // Special case of object, is_object will return false
-                $result[$key] = array('incomplete-object', $this->getClassNameFromIncomplete($value));
             } else {
                 $result[$key] = array('string', (string) $value);
             }

ExceptionHandler.php

@@ -94,7 +94,7 @@ class ExceptionHandler
      *
      * @param string $format The format for links to source files
      *
-     * @return string The previous file link format.
+     * @return string The previous file link format
      */
     public function setFileLinkFormat($format)
     {
@@ -319,6 +319,7 @@ EOF;
                 border-bottom:1px solid #ccc;
                 border-right:1px solid #ccc;
                 border-left:1px solid #ccc;
+                word-wrap: break-word;
             }
             .sf-reset .block_exception { background-color:#ddd; color: #333; padding:20px;
                 -webkit-border-top-left-radius: 16px;

Resources/ext/tests/001.phpt

@@ -1,14 +1,14 @@
 --TEST--
 Test symfony_zval_info API
 --SKIPIF--
-<?php if (!extension_loaded("symfony_debug")) print "skip"; ?>
+<?php if (!extension_loaded('symfony_debug')) print 'skip'; ?>
 --FILE--
 <?php
 
 $int = 42;
 $float = 42.42;
-$str = "foobar";
-$object = new StdClass;
+$str = 'foobar';
+$object = new StdClass();
 $array = array('foo', 'bar');
 $resource = tmpfile();
 $null = null;
@@ -17,15 +17,17 @@ $bool = true;
 $anotherint = 42;
 $refcount2 = &$anotherint;
 
-$var = array('int' => $int,
-			 'float' => $float,
-			 'str' => $str,
-			 'object' => $object,
-			 'array' => $array,
-			 'resource' => $resource,
-			 'null' => $null,
-			 'bool' => $bool,
-			 'refcount' => &$refcount2);
+$var = array(
+    'int' => $int,
+    'float' => $float,
+    'str' => $str,
+    'object' => $object,
+    'array' => $array,
+    'resource' => $resource,
+    'null' => $null,
+    'bool' => $bool,
+    'refcount' => &$refcount2,
+);
 
 var_dump(symfony_zval_info('int', $var));
 var_dump(symfony_zval_info('float', $var));

Resources/ext/tests/002.phpt

@@ -1,7 +1,7 @@
 --TEST--
 Test symfony_debug_backtrace in case of fatal error
 --SKIPIF--
-<?php if (!extension_loaded("symfony_debug")) print "skip"; ?>
+<?php if (!extension_loaded('symfony_debug')) print 'skip'; ?>
 --FILE--
 <?php
 
@@ -18,7 +18,6 @@ function foo()
 function bt()
 {
     print_r(symfony_debug_backtrace());
-
 }
 
 register_shutdown_function('bt');

Resources/ext/tests/002_1.phpt

@@ -1,7 +1,7 @@
 --TEST--
 Test symfony_debug_backtrace in case of non fatal error
 --SKIPIF--
-<?php if (!extension_loaded("symfony_debug")) print "skip"; ?>
+<?php if (!extension_loaded('symfony_debug')) print 'skip'; ?>
 --FILE--
 <?php
 
@@ -13,7 +13,6 @@ function bar()
 function bt()
 {
     print_r(symfony_debug_backtrace());
-
 }
 
 bar();

Resources/ext/tests/003.phpt

@@ -1,7 +1,7 @@
 --TEST--
 Test ErrorHandler in case of fatal error
 --SKIPIF--
-<?php if (!extension_loaded("symfony_debug")) print "skip"; ?>
+<?php if (!extension_loaded('symfony_debug')) print 'skip'; ?>
 --FILE--
 <?php
 

Tests/DebugClassLoaderTest.php

@@ -13,12 +13,11 @@ namespace Symfony\Component\Debug\Tests;
 
 use Symfony\Component\Debug\DebugClassLoader;
 use Symfony\Component\Debug\ErrorHandler;
-use Symfony\Component\Debug\Exception\ContextErrorException;
 
 class DebugClassLoaderTest extends \PHPUnit_Framework_TestCase
 {
     /**
-     * @var int Error reporting level before running tests.
+     * @var int Error reporting level before running tests
      */
     private $errorReporting;
 

Tests/ErrorHandlerTest.php

@@ -413,6 +413,24 @@ class ErrorHandlerTest extends \PHPUnit_Framework_TestCase
         }
     }
 
+    /**
+     * @requires PHP 7
+     */
+    public function testHandleErrorException()
+    {
+        $exception = new \Error("Class 'Foo' not found");
+
+        $handler = new ErrorHandler();
+        $handler->setExceptionHandler(function () use (&$args) {
+            $args = func_get_args();
+        });
+
+        $handler->handleException($exception);
+
+        $this->assertInstanceOf('Symfony\Component\Debug\Exception\ClassNotFoundException', $args[0]);
+        $this->assertStringStartsWith("Attempted to load class \"Foo\" from the global namespace.\nDid you forget a \"use\" statement", $args[0]->getMessage());
+    }
+
     public function testHandleFatalErrorOnHHVM()
     {
         try {

Tests/MockExceptionHandler.php

@@ -13,7 +13,7 @@ namespace Symfony\Component\Debug\Tests;
 
 use Symfony\Component\Debug\ExceptionHandler;
 
-class MockExceptionHandler extends Exceptionhandler
+class MockExceptionHandler extends ExceptionHandler
 {
     public $e;