Merge branch '2.8' into 3.4

* 2.8: Fixed typo Fix ini_get() for boolean values
Fix ini_get() for boolean values
2026-03-25 17:52:07 +01:00 · 2018-10-31 10:06:03 +01:00 · 2018-10-30 17:24:01 +01:00 · 2018-10-02 18:33:53 +02:00 · 2018-10-02 18:22:14 +02:00 · 2018-10-02 00:12:00 -03:00
34 changed files with 738 additions and 352 deletions
--- a/Debug.php
+++ b/Debug.php
@@ -23,10 +23,7 @@ class Debug
    /**
     * Enables the debug tools.
     *
-     * This method registers an error handler and an exception handler.
-     *
-     * If the Symfony ClassLoader component is available, a special
-     * class loader is also registered.
+     * This method registers an error handler, an exception handler and a special class loader.
     *
     * @param int  $errorReportingLevel The level of error reporting you want
     * @param bool $displayErrors       Whether to display errors (for development) or just log them (for production)
@@ -45,10 +42,10 @@ class Debug
            error_reporting(E_ALL);
        }

-        if ('cli' !== PHP_SAPI) {
+        if (!\in_array(\PHP_SAPI, array('cli', 'phpdbg'), true)) {
            ini_set('display_errors', 0);
            ExceptionHandler::register();
-        } elseif ($displayErrors && (!ini_get('log_errors') || ini_get('error_log'))) {
+        } elseif ($displayErrors && (!filter_var(ini_get('log_errors'), FILTER_VALIDATE_BOOLEAN) || ini_get('error_log'))) {
            // CLI - display errors only if they're not already logged to STDERR
            ini_set('display_errors', 1);
        }
--- a/DebugClassLoader.php
+++ b/DebugClassLoader.php
@@ -28,22 +28,23 @@ class DebugClassLoader
    private $isFinder;
    private $loaded = array();
    private static $caseCheck;
+    private static $checkedClasses = array();
    private static $final = array();
    private static $finalMethods = array();
    private static $deprecated = array();
    private static $internal = array();
    private static $internalMethods = array();
-    private static $php7Reserved = array('int', 'float', 'bool', 'string', 'true', 'false', 'null');
+    private static $php7Reserved = array('int' => 1, 'float' => 1, 'bool' => 1, 'string' => 1, 'true' => 1, 'false' => 1, 'null' => 1);
    private static $darwinCache = array('/' => array('/', array()));

    public function __construct(callable $classLoader)
    {
        $this->classLoader = $classLoader;
-        $this->isFinder = is_array($classLoader) && method_exists($classLoader[0], 'findFile');
+        $this->isFinder = \is_array($classLoader) && method_exists($classLoader[0], 'findFile');

        if (!isset(self::$caseCheck)) {
-            $file = file_exists(__FILE__) ? __FILE__ : rtrim(realpath('.'), DIRECTORY_SEPARATOR);
-            $i = strrpos($file, DIRECTORY_SEPARATOR);
+            $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);
@@ -52,7 +53,7 @@ class DebugClassLoader
            if (false === $test || false === $i) {
                // filesystem is case sensitive
                self::$caseCheck = 0;
-            } elseif (substr($test, -strlen($file)) === $file) {
+            } elseif (substr($test, -\strlen($file)) === $file) {
                // filesystem is case insensitive and realpath() normalizes the case of characters
                self::$caseCheck = 1;
            } elseif (false !== stripos(PHP_OS, 'darwin')) {
@@ -84,7 +85,7 @@ class DebugClassLoader
        class_exists('Symfony\Component\Debug\ErrorHandler');
        class_exists('Psr\Log\LogLevel');

-        if (!is_array($functions = spl_autoload_functions())) {
+        if (!\is_array($functions = spl_autoload_functions())) {
            return;
        }

@@ -93,7 +94,7 @@ class DebugClassLoader
        }

        foreach ($functions as $function) {
-            if (!is_array($function) || !$function[0] instanceof self) {
+            if (!\is_array($function) || !$function[0] instanceof self) {
                $function = array(new static($function), 'loadClass');
            }

@@ -106,7 +107,7 @@ class DebugClassLoader
     */
    public static function disable()
    {
-        if (!is_array($functions = spl_autoload_functions())) {
+        if (!\is_array($functions = spl_autoload_functions())) {
            return;
        }

@@ -115,7 +116,7 @@ class DebugClassLoader
        }

        foreach ($functions as $function) {
-            if (is_array($function) && $function[0] instanceof self) {
+            if (\is_array($function) && $function[0] instanceof self) {
                $function = $function[0]->getClassLoader();
            }

@@ -128,8 +129,6 @@ class DebugClassLoader
     *
     * @param string $class The name of the class
     *
-     * @return bool|null True, if loaded
-     *
     * @throws \RuntimeException
     */
    public function loadClass($class)
@@ -139,220 +138,271 @@ class DebugClassLoader
        try {
            if ($this->isFinder && !isset($this->loaded[$class])) {
                $this->loaded[$class] = true;
-                if ($file = $this->classLoader[0]->findFile($class)) {
+                if ($file = $this->classLoader[0]->findFile($class) ?: false) {
+                    $wasCached = \function_exists('opcache_is_script_cached') && @opcache_is_script_cached($file);
+
                    require $file;
+
+                    if ($wasCached) {
+                        return;
+                    }
                }
            } else {
-                call_user_func($this->classLoader, $class);
+                \call_user_func($this->classLoader, $class);
                $file = false;
            }
        } finally {
            error_reporting($e);
        }

-        $exists = class_exists($class, false) || interface_exists($class, false) || trait_exists($class, false);
+        $this->checkClass($class, $file);
+    }

-        if ($class && '\\' === $class[0]) {
+    private function checkClass($class, $file = null)
+    {
+        $exists = null === $file || \class_exists($class, false) || \interface_exists($class, false) || \trait_exists($class, false);
+
+        if (null !== $file && $class && '\\' === $class[0]) {
            $class = substr($class, 1);
        }

        if ($exists) {
+            if (isset(self::$checkedClasses[$class])) {
+                return;
+            }
+            self::$checkedClasses[$class] = true;
+
            $refl = new \ReflectionClass($class);
+            if (null === $file && $refl->isInternal()) {
+                return;
+            }
            $name = $refl->getName();

-            if ($name !== $class && 0 === strcasecmp($name, $class)) {
+            if ($name !== $class && 0 === \strcasecmp($name, $class)) {
                throw new \RuntimeException(sprintf('Case mismatch between loaded and declared class names: "%s" vs "%s".', $class, $name));
            }

-            // Don't trigger deprecations for classes in the same vendor
-            if (2 > $len = 1 + (strpos($name, '\\') ?: strpos($name, '_'))) {
-                $len = 0;
-                $ns = '';
+            $deprecations = $this->checkAnnotations($refl, $name);
+
+            if (isset(self::$php7Reserved[\strtolower($refl->getShortName())])) {
+                $deprecations[] = sprintf('The "%s" class uses the reserved name "%s", it will break on PHP 7 and higher', $name, $refl->getShortName());
+            }
+
+            foreach ($deprecations as $message) {
+                @trigger_error($message, E_USER_DEPRECATED);
+            }
+        }
+
+        if (!$file) {
+            return;
+        }
+
+        if (!$exists) {
+            if (false !== strpos($class, '/')) {
+                throw new \RuntimeException(sprintf('Trying to autoload a class with an invalid name "%s". Be careful that the namespace separator is "\" in PHP, not "/".', $class));
+            }
+
+            throw new \RuntimeException(sprintf('The autoloader expected class "%s" to be defined in file "%s". The file was found but the class was not in it, the class name or namespace probably has a typo.', $class, $file));
+        }
+
+        if (self::$caseCheck && $message = $this->checkCase($refl, $file, $class)) {
+            throw new \RuntimeException(sprintf('Case mismatch between class and real file names: "%s" vs "%s" in "%s".', $message[0], $message[1], $message[2]));
+        }
+    }
+
+    public function checkAnnotations(\ReflectionClass $refl, $class)
+    {
+        $deprecations = array();
+
+        // Don't trigger deprecations for classes in the same vendor
+        if (2 > $len = 1 + (\strpos($class, '\\') ?: \strpos($class, '_'))) {
+            $len = 0;
+            $ns = '';
+        } else {
+            $ns = \substr($class, 0, $len);
+        }
+
+        // Detect annotations on the class
+        if (false !== $doc = $refl->getDocComment()) {
+            foreach (array('final', 'deprecated', 'internal') as $annotation) {
+                if (false !== \strpos($doc, $annotation) && preg_match('#\n \* @'.$annotation.'(?:( .+?)\.?)?\r?\n \*(?: @|/$)#s', $doc, $notice)) {
+                    self::${$annotation}[$class] = isset($notice[1]) ? preg_replace('#\s*\r?\n \* +#', ' ', $notice[1]) : '';
+                }
+            }
+        }
+
+        $parent = \get_parent_class($class);
+        $parentAndOwnInterfaces = $this->getOwnInterfaces($class, $parent);
+        if ($parent) {
+            $parentAndOwnInterfaces[$parent] = $parent;
+
+            if (!isset(self::$checkedClasses[$parent])) {
+                $this->checkClass($parent);
+            }
+
+            if (isset(self::$final[$parent])) {
+                $deprecations[] = sprintf('The "%s" class is considered final%s. It may change without further notice as of its next major version. You should not extend it from "%s".', $parent, self::$final[$parent], $class);
+            }
+        }
+
+        // Detect if the parent is annotated
+        foreach ($parentAndOwnInterfaces + \class_uses($class, false) as $use) {
+            if (!isset(self::$checkedClasses[$use])) {
+                $this->checkClass($use);
+            }
+            if (isset(self::$deprecated[$use]) && \strncmp($ns, $use, $len)) {
+                $type = class_exists($class, false) ? 'class' : (interface_exists($class, false) ? 'interface' : 'trait');
+                $verb = class_exists($use, false) || interface_exists($class, false) ? 'extends' : (interface_exists($use, false) ? 'implements' : 'uses');
+
+                $deprecations[] = sprintf('The "%s" %s %s "%s" that is deprecated%s.', $class, $type, $verb, $use, self::$deprecated[$use]);
+            }
+            if (isset(self::$internal[$use]) && \strncmp($ns, $use, $len)) {
+                $deprecations[] = sprintf('The "%s" %s is considered internal%s. It may change without further notice. You should not use it from "%s".', $use, class_exists($use, false) ? 'class' : (interface_exists($use, false) ? 'interface' : 'trait'), self::$internal[$use], $class);
+            }
+        }
+
+        if (\trait_exists($class)) {
+            return $deprecations;
+        }
+
+        // Inherit @final and @internal annotations for methods
+        self::$finalMethods[$class] = array();
+        self::$internalMethods[$class] = array();
+        foreach ($parentAndOwnInterfaces as $use) {
+            foreach (array('finalMethods', 'internalMethods') as $property) {
+                if (isset(self::${$property}[$use])) {
+                    self::${$property}[$class] = self::${$property}[$class] ? self::${$property}[$use] + self::${$property}[$class] : self::${$property}[$use];
+                }
+            }
+        }
+
+        foreach ($refl->getMethods(\ReflectionMethod::IS_PUBLIC | \ReflectionMethod::IS_PROTECTED) as $method) {
+            if ($method->class !== $class) {
+                continue;
+            }
+
+            if ($parent && isset(self::$finalMethods[$parent][$method->name])) {
+                list($declaringClass, $message) = self::$finalMethods[$parent][$method->name];
+                $deprecations[] = sprintf('The "%s::%s()" method is considered final%s. It may change without further notice as of its next major version. You should not extend it from "%s".', $declaringClass, $method->name, $message, $class);
+            }
+
+            if (isset(self::$internalMethods[$class][$method->name])) {
+                list($declaringClass, $message) = self::$internalMethods[$class][$method->name];
+                if (\strncmp($ns, $declaringClass, $len)) {
+                    $deprecations[] = sprintf('The "%s::%s()" method is considered internal%s. It may change without further notice. You should not extend it from "%s".', $declaringClass, $method->name, $message, $class);
+                }
+            }
+
+            // Detect method annotations
+            if (false === $doc = $method->getDocComment()) {
+                continue;
+            }
+
+            foreach (array('final', 'internal') as $annotation) {
+                if (false !== \strpos($doc, $annotation) && preg_match('#\n\s+\* @'.$annotation.'(?:( .+?)\.?)?\r?\n\s+\*(?: @|/$)#s', $doc, $notice)) {
+                    $message = isset($notice[1]) ? preg_replace('#\s*\r?\n \* +#', ' ', $notice[1]) : '';
+                    self::${$annotation.'Methods'}[$class][$method->name] = array($class, $message);
+                }
+            }
+        }
+
+        return $deprecations;
+    }
+
+    public function checkCase(\ReflectionClass $refl, $file, $class)
+    {
+        $real = explode('\\', $class.strrchr($file, '.'));
+        $tail = explode(\DIRECTORY_SEPARATOR, str_replace('/', \DIRECTORY_SEPARATOR, $file));
+
+        $i = \count($tail) - 1;
+        $j = \count($real) - 1;
+
+        while (isset($tail[$i], $real[$j]) && $tail[$i] === $real[$j]) {
+            --$i;
+            --$j;
+        }
+
+        array_splice($tail, 0, $i + 1);
+
+        if (!$tail) {
+            return;
+        }
+
+        $tail = \DIRECTORY_SEPARATOR.implode(\DIRECTORY_SEPARATOR, $tail);
+        $tailLen = \strlen($tail);
+        $real = $refl->getFileName();
+
+        if (2 === self::$caseCheck) {
+            $real = $this->darwinRealpath($real);
+        }
+
+        if (0 === substr_compare($real, $tail, -$tailLen, $tailLen, true)
+            && 0 !== substr_compare($real, $tail, -$tailLen, $tailLen, false)
+        ) {
+            return array(substr($tail, -$tailLen + 1), substr($real, -$tailLen + 1), substr($real, 0, -$tailLen + 1));
+        }
+    }
+
+    /**
+     * `realpath` on MacOSX doesn't normalize the case of characters.
+     */
+    private function darwinRealpath($real)
+    {
+        $i = 1 + strrpos($real, '/');
+        $file = substr($real, $i);
+        $real = substr($real, 0, $i);
+
+        if (isset(self::$darwinCache[$real])) {
+            $kDir = $real;
+        } else {
+            $kDir = strtolower($real);
+
+            if (isset(self::$darwinCache[$kDir])) {
+                $real = self::$darwinCache[$kDir][0];
            } else {
-                $ns = substr($name, 0, $len);
-            }
+                $dir = getcwd();
+                chdir($real);
+                $real = getcwd().'/';
+                chdir($dir);

-            // Detect annotations on the class
-            if (false !== $doc = $refl->getDocComment()) {
-                foreach (array('final', 'deprecated', 'internal') as $annotation) {
-                    if (false !== strpos($doc, '@'.$annotation) && preg_match('#\n \* @'.$annotation.'(?:( .+?)\.?)?\r?\n \*(?: @|/$)#s', $doc, $notice)) {
-                        self::${$annotation}[$name] = isset($notice[1]) ? preg_replace('#\s*\r?\n \* +#', ' ', $notice[1]) : '';
+                $dir = $real;
+                $k = $kDir;
+                $i = \strlen($dir) - 1;
+                while (!isset(self::$darwinCache[$k])) {
+                    self::$darwinCache[$k] = array($dir, array());
+                    self::$darwinCache[$dir] = &self::$darwinCache[$k];
+
+                    while ('/' !== $dir[--$i]) {
                    }
+                    $k = substr($k, 0, ++$i);
+                    $dir = substr($dir, 0, $i--);
                }
            }
-
-            $parentAndTraits = class_uses($name, false);
-            if ($parent = get_parent_class($class)) {
-                $parentAndTraits[] = $parent;
-
-                if (isset(self::$final[$parent])) {
-                    @trigger_error(sprintf('The "%s" class is considered final%s. It may change without further notice as of its next major version. You should not extend it from "%s".', $parent, self::$final[$parent], $name), E_USER_DEPRECATED);
-                }
-            }
-
-            // Detect if the parent is annotated
-            foreach ($parentAndTraits + $this->getOwnInterfaces($name, $parent) as $use) {
-                if (isset(self::$deprecated[$use]) && strncmp($ns, $use, $len)) {
-                    $type = class_exists($name, false) ? 'class' : (interface_exists($name, false) ? 'interface' : 'trait');
-                    $verb = class_exists($use, false) || interface_exists($name, false) ? 'extends' : (interface_exists($use, false) ? 'implements' : 'uses');
-
-                    @trigger_error(sprintf('The "%s" %s %s "%s" that is deprecated%s.', $name, $type, $verb, $use, self::$deprecated[$use]), E_USER_DEPRECATED);
-                }
-                if (isset(self::$internal[$use]) && strncmp($ns, $use, $len)) {
-                    @trigger_error(sprintf('The "%s" %s is considered internal%s. It may change without further notice. You should not use it from "%s".', $use, class_exists($use, false) ? 'class' : (interface_exists($use, false) ? 'interface' : 'trait'), self::$internal[$use], $name), E_USER_DEPRECATED);
-                }
-            }
-
-            // Inherit @final and @internal annotations for methods
-            self::$finalMethods[$name] = array();
-            self::$internalMethods[$name] = array();
-            foreach ($parentAndTraits as $use) {
-                foreach (array('finalMethods', 'internalMethods') as $property) {
-                    if (isset(self::${$property}[$use])) {
-                        self::${$property}[$name] = array_merge(self::${$property}[$name], self::${$property}[$use]);
-                    }
-                }
-            }
-
-            $isClass = class_exists($name, false);
-            foreach ($refl->getMethods(\ReflectionMethod::IS_PUBLIC | \ReflectionMethod::IS_PROTECTED) as $method) {
-                if ($method->class !== $name) {
-                    continue;
-                }
-
-                // Method from a trait
-                if ($method->getFilename() !== $refl->getFileName()) {
-                    continue;
-                }
-
-                if ($isClass && $parent && isset(self::$finalMethods[$parent][$method->name])) {
-                    list($declaringClass, $message) = self::$finalMethods[$parent][$method->name];
-                    @trigger_error(sprintf('The "%s::%s()" method is considered final%s. It may change without further notice as of its next major version. You should not extend it from "%s".', $declaringClass, $method->name, $message, $name), E_USER_DEPRECATED);
-                }
-
-                foreach ($parentAndTraits as $use) {
-                    if (isset(self::$internalMethods[$use][$method->name])) {
-                        list($declaringClass, $message) = self::$internalMethods[$use][$method->name];
-                        if (strncmp($ns, $declaringClass, $len)) {
-                            @trigger_error(sprintf('The "%s::%s()" method is considered internal%s. It may change without further notice. You should not extend it from "%s".', $declaringClass, $method->name, $message, $name), E_USER_DEPRECATED);
-                        }
-                    }
-                }
-
-                // Detect method annotations
-                if (false === $doc = $method->getDocComment()) {
-                    continue;
-                }
-
-                foreach (array('final', 'internal') as $annotation) {
-                    if (false !== strpos($doc, '@'.$annotation) && preg_match('#\n\s+\* @'.$annotation.'(?:( .+?)\.?)?\r?\n\s+\*(?: @|/$)#s', $doc, $notice)) {
-                        $message = isset($notice[1]) ? preg_replace('#\s*\r?\n \* +#', ' ', $notice[1]) : '';
-                        self::${$annotation.'Methods'}[$name][$method->name] = array($name, $message);
-                    }
-                }
-            }
-
-            if (in_array(strtolower($refl->getShortName()), self::$php7Reserved)) {
-                @trigger_error(sprintf('The "%s" class uses the reserved name "%s", it will break on PHP 7 and higher', $name, $refl->getShortName()), E_USER_DEPRECATED);
-            }
        }

-        if ($file) {
-            if (!$exists) {
-                if (false !== strpos($class, '/')) {
-                    throw new \RuntimeException(sprintf('Trying to autoload a class with an invalid name "%s". Be careful that the namespace separator is "\" in PHP, not "/".', $class));
-                }
+        $dirFiles = self::$darwinCache[$kDir][1];

-                throw new \RuntimeException(sprintf('The autoloader expected class "%s" to be defined in file "%s". The file was found but the class was not in it, the class name or namespace probably has a typo.', $class, $file));
-            }
-            if (self::$caseCheck) {
-                $real = explode('\\', $class.strrchr($file, '.'));
-                $tail = explode(DIRECTORY_SEPARATOR, str_replace('/', DIRECTORY_SEPARATOR, $file));
-
-                $i = count($tail) - 1;
-                $j = count($real) - 1;
-
-                while (isset($tail[$i], $real[$j]) && $tail[$i] === $real[$j]) {
-                    --$i;
-                    --$j;
-                }
-
-                array_splice($tail, 0, $i + 1);
-            }
-            if (self::$caseCheck && $tail) {
-                $tail = DIRECTORY_SEPARATOR.implode(DIRECTORY_SEPARATOR, $tail);
-                $tailLen = strlen($tail);
-                $real = $refl->getFileName();
-
-                if (2 === self::$caseCheck) {
-                    // realpath() on MacOSX doesn't normalize the case of characters
-
-                    $i = 1 + strrpos($real, '/');
-                    $file = substr($real, $i);
-                    $real = substr($real, 0, $i);
-
-                    if (isset(self::$darwinCache[$real])) {
-                        $kDir = $real;
-                    } else {
-                        $kDir = strtolower($real);
-
-                        if (isset(self::$darwinCache[$kDir])) {
-                            $real = self::$darwinCache[$kDir][0];
-                        } else {
-                            $dir = getcwd();
-                            chdir($real);
-                            $real = getcwd().'/';
-                            chdir($dir);
-
-                            $dir = $real;
-                            $k = $kDir;
-                            $i = strlen($dir) - 1;
-                            while (!isset(self::$darwinCache[$k])) {
-                                self::$darwinCache[$k] = array($dir, array());
-                                self::$darwinCache[$dir] = &self::$darwinCache[$k];
-
-                                while ('/' !== $dir[--$i]) {
-                                }
-                                $k = substr($k, 0, ++$i);
-                                $dir = substr($dir, 0, $i--);
-                            }
-                        }
-                    }
-
-                    $dirFiles = self::$darwinCache[$kDir][1];
-
-                    if (isset($dirFiles[$file])) {
-                        $kFile = $file;
-                    } else {
-                        $kFile = strtolower($file);
-
-                        if (!isset($dirFiles[$kFile])) {
-                            foreach (scandir($real, 2) as $f) {
-                                if ('.' !== $f[0]) {
-                                    $dirFiles[$f] = $f;
-                                    if ($f === $file) {
-                                        $kFile = $k = $file;
-                                    } elseif ($f !== $k = strtolower($f)) {
-                                        $dirFiles[$k] = $f;
-                                    }
-                                }
-                            }
-                            self::$darwinCache[$kDir][1] = $dirFiles;
-                        }
-                    }
-
-                    $real .= $dirFiles[$kFile];
-                }
-
-                if (0 === substr_compare($real, $tail, -$tailLen, $tailLen, true)
-                  && 0 !== substr_compare($real, $tail, -$tailLen, $tailLen, false)
-                ) {
-                    throw new \RuntimeException(sprintf('Case mismatch between class and real file names: "%s" vs "%s" in "%s".', substr($tail, -$tailLen + 1), substr($real, -$tailLen + 1), substr($real, 0, -$tailLen + 1)));
-                }
-            }
-
-            return true;
+        if (isset($dirFiles[$file])) {
+            return $real .= $dirFiles[$file];
        }
+
+        $kFile = strtolower($file);
+
+        if (!isset($dirFiles[$kFile])) {
+            foreach (scandir($real, 2) as $f) {
+                if ('.' !== $f[0]) {
+                    $dirFiles[$f] = $f;
+                    if ($f === $file) {
+                        $kFile = $k = $file;
+                    } elseif ($f !== $k = strtolower($f)) {
+                        $dirFiles[$k] = $f;
+                    }
+                }
+            }
+            self::$darwinCache[$kDir][1] = $dirFiles;
+        }
+
+        return $real .= $dirFiles[$kFile];
    }

    /**
--- a/ErrorHandler.php
+++ b/ErrorHandler.php
@@ -11,17 +11,17 @@

 namespace Symfony\Component\Debug;

-use Psr\Log\LogLevel;
 use Psr\Log\LoggerInterface;
+use Psr\Log\LogLevel;
 use Symfony\Component\Debug\Exception\ContextErrorException;
 use Symfony\Component\Debug\Exception\FatalErrorException;
 use Symfony\Component\Debug\Exception\FatalThrowableError;
 use Symfony\Component\Debug\Exception\OutOfMemoryException;
 use Symfony\Component\Debug\Exception\SilencedErrorContext;
-use Symfony\Component\Debug\FatalErrorHandler\UndefinedFunctionFatalErrorHandler;
-use Symfony\Component\Debug\FatalErrorHandler\UndefinedMethodFatalErrorHandler;
 use Symfony\Component\Debug\FatalErrorHandler\ClassNotFoundFatalErrorHandler;
 use Symfony\Component\Debug\FatalErrorHandler\FatalErrorHandlerInterface;
+use Symfony\Component\Debug\FatalErrorHandler\UndefinedFunctionFatalErrorHandler;
+use Symfony\Component\Debug\FatalErrorHandler\UndefinedMethodFatalErrorHandler;

 /**
 * A generic ErrorHandler for the PHP engine.
@@ -130,14 +130,28 @@ class ErrorHandler
            $handler->isRoot = true;
        }

-        if ($handlerIsNew && is_array($prev) && $prev[0] instanceof self) {
+        if ($handlerIsNew && \is_array($prev) && $prev[0] instanceof self) {
            $handler = $prev[0];
            $replace = false;
        }
-        if ($replace || !$prev) {
-            $handler->setExceptionHandler(set_exception_handler(array($handler, 'handleException')));
-        } else {
+        if (!$replace && $prev) {
            restore_error_handler();
+            $handlerIsRegistered = \is_array($prev) && $handler === $prev[0];
+        } else {
+            $handlerIsRegistered = true;
+        }
+        if (\is_array($prev = set_exception_handler(array($handler, 'handleException'))) && $prev[0] instanceof self) {
+            restore_exception_handler();
+            if (!$handlerIsRegistered) {
+                $handler = $prev[0];
+            } elseif ($handler !== $prev[0] && $replace) {
+                set_exception_handler(array($handler, 'handleException'));
+                $p = $prev[0]->setExceptionHandler(null);
+                $handler->setExceptionHandler($p);
+                $prev[0]->setExceptionHandler($p);
+            }
+        } else {
+            $handler->setExceptionHandler($prev);
        }

        $handler->throwAt(E_ALL & $handler->thrownErrors, true);
@@ -166,7 +180,7 @@ class ErrorHandler
    {
        $loggers = array();

-        if (is_array($levels)) {
+        if (\is_array($levels)) {
            foreach ($levels as $type => $logLevel) {
                if (empty($this->loggers[$type][0]) || $replace || $this->loggers[$type][0] === $this->bootstrappingLogger) {
                    $loggers[$type] = array($logger, $logLevel);
@@ -206,7 +220,7 @@ class ErrorHandler
            if (!isset($prev[$type])) {
                throw new \InvalidArgumentException('Unknown error type: '.$type);
            }
-            if (!is_array($log)) {
+            if (!\is_array($log)) {
                $log = array($log);
            } elseif (!array_key_exists(0, $log)) {
                throw new \InvalidArgumentException('No logger provided');
@@ -339,7 +353,7 @@ class ErrorHandler
    {
        if ($prev !== $this->thrownErrors | $this->loggedErrors) {
            $handler = set_error_handler('var_dump');
-            $handler = is_array($handler) ? $handler[0] : null;
+            $handler = \is_array($handler) ? $handler[0] : null;
            restore_error_handler();
            if ($handler === $this) {
                restore_error_handler();
@@ -369,18 +383,20 @@ class ErrorHandler
    public function handleError($type, $message, $file, $line)
    {
        // Level is the current error reporting level to manage silent error.
+        $level = error_reporting();
+        $silenced = 0 === ($level & $type);
        // Strong errors are not authorized to be silenced.
-        $level = error_reporting() | E_RECOVERABLE_ERROR | E_USER_ERROR | E_DEPRECATED | E_USER_DEPRECATED;
+        $level |= E_RECOVERABLE_ERROR | E_USER_ERROR | E_DEPRECATED | E_USER_DEPRECATED;
        $log = $this->loggedErrors & $type;
        $throw = $this->thrownErrors & $type & $level;
        $type &= $level | $this->screamedErrors;

        if (!$type || (!$log && !$throw)) {
-            return $type && $log;
+            return !$silenced && $type && $log;
        }
        $scope = $this->scopedErrors & $type;

-        if (4 < $numArgs = func_num_args()) {
+        if (4 < $numArgs = \func_num_args()) {
            $context = $scope ? (func_get_arg(4) ?: array()) : array();
            $backtrace = 5 < $numArgs ? func_get_arg(5) : null; // defined on HHVM
        } else {
@@ -510,7 +526,7 @@ class ErrorHandler
            }
        }

-        return $type && $log;
+        return !$silenced && $type && $log;
    }

    /**
@@ -530,6 +546,7 @@ class ErrorHandler
            $exception = new FatalThrowableError($exception);
        }
        $type = $exception instanceof FatalErrorException ? $exception->getSeverity() : E_ERROR;
+        $handlerException = null;

        if (($this->loggedErrors & $type) || $exception instanceof FatalThrowableError) {
            if ($exception instanceof FatalErrorException) {
@@ -564,18 +581,21 @@ class ErrorHandler
                }
            }
        }
-        if (empty($this->exceptionHandler)) {
-            throw $exception; // Give back $exception to the native handler
-        }
+        $exceptionHandler = $this->exceptionHandler;
+        $this->exceptionHandler = null;
        try {
-            call_user_func($this->exceptionHandler, $exception);
+            if (null !== $exceptionHandler) {
+                return \call_user_func($exceptionHandler, $exception);
+            }
+            $handlerException = $handlerException ?: $exception;
        } catch (\Exception $handlerException) {
        } catch (\Throwable $handlerException) {
        }
-        if (isset($handlerException)) {
-            $this->exceptionHandler = null;
-            $this->handleException($handlerException);
+        if ($exception === $handlerException) {
+            self::$reservedMemory = null; // Disable the fatal error handler
+            throw $exception; // Give back $exception to the native handler
        }
+        $this->handleException($handlerException);
    }

    /**
@@ -591,15 +611,39 @@ class ErrorHandler
            return;
        }

-        self::$reservedMemory = null;
+        $handler = self::$reservedMemory = null;
+        $handlers = array();
+        $previousHandler = null;
+        $sameHandlerLimit = 10;

-        $handler = set_error_handler('var_dump');
-        $handler = is_array($handler) ? $handler[0] : null;
-        restore_error_handler();
+        while (!\is_array($handler) || !$handler[0] instanceof self) {
+            $handler = set_exception_handler('var_dump');
+            restore_exception_handler();

-        if (!$handler instanceof self) {
+            if (!$handler) {
+                break;
+            }
+            restore_exception_handler();
+
+            if ($handler !== $previousHandler) {
+                array_unshift($handlers, $handler);
+                $previousHandler = $handler;
+            } elseif (0 === --$sameHandlerLimit) {
+                $handler = null;
+                break;
+            }
+        }
+        foreach ($handlers as $h) {
+            set_exception_handler($h);
+        }
+        if (!$handler) {
            return;
        }
+        if ($handler !== $h) {
+            $handler[0]->setExceptionHandler($h);
+        }
+        $handler = $handler[0];
+        $handlers = array();

        if ($exit = null === $error) {
            $error = error_get_last();
@@ -713,7 +757,7 @@ class ErrorHandler

        for ($i = 0; isset($backtrace[$i]); ++$i) {
            if (isset($backtrace[$i]['file'], $backtrace[$i]['line']) && $backtrace[$i]['line'] === $line && $backtrace[$i]['file'] === $file) {
-                $lightTrace = array_slice($lightTrace, 1 + $i);
+                $lightTrace = \array_slice($lightTrace, 1 + $i);
                break;
            }
        }
--- a/Exception/ClassNotFoundException.php
+++ b/Exception/ClassNotFoundException.php
@@ -26,6 +26,9 @@ class ClassNotFoundException extends FatalErrorException
            $previous->getSeverity(),
            $previous->getFile(),
            $previous->getLine(),
+            null,
+            true,
+            null,
            $previous->getPrevious()
        );
        $this->setTrace($previous->getTrace());
--- a/Exception/ContextErrorException.php
+++ b/Exception/ContextErrorException.php
@@ -33,7 +33,7 @@ class ContextErrorException extends \ErrorException
     */
    public function getContext()
    {
-        @trigger_error(sprintf('The %s class is deprecated since version 3.3 and will be removed in 4.0.', __CLASS__), E_USER_DEPRECATED);
+        @trigger_error(sprintf('The %s class is deprecated since Symfony 3.3 and will be removed in 4.0.', __CLASS__), E_USER_DEPRECATED);

        return $this->context;
    }
--- a/Exception/FatalErrorException.php
+++ b/Exception/FatalErrorException.php
@@ -18,9 +18,9 @@ namespace Symfony\Component\Debug\Exception;
 */
 class FatalErrorException extends \ErrorException
 {
-    public function __construct($message, $code, $severity, $filename, $lineno, $traceOffset = null, $traceArgs = true, array $trace = null)
+    public function __construct($message, $code, $severity, $filename, $lineno, $traceOffset = null, $traceArgs = true, array $trace = null, $previous = null)
    {
-        parent::__construct($message, $code, $severity, $filename, $lineno);
+        parent::__construct($message, $code, $severity, $filename, $lineno, $previous);

        if (null !== $trace) {
            if (!$traceArgs) {
@@ -31,7 +31,7 @@ class FatalErrorException extends \ErrorException

            $this->setTrace($trace);
        } elseif (null !== $traceOffset) {
-            if (function_exists('xdebug_get_function_stack')) {
+            if (\function_exists('xdebug_get_function_stack')) {
                $trace = xdebug_get_function_stack();
                if (0 < $traceOffset) {
                    array_splice($trace, -$traceOffset);
@@ -60,7 +60,7 @@ class FatalErrorException extends \ErrorException

                unset($frame);
                $trace = array_reverse($trace);
-            } elseif (function_exists('symfony_debug_backtrace')) {
+            } elseif (\function_exists('symfony_debug_backtrace')) {
                $trace = symfony_debug_backtrace();
                if (0 < $traceOffset) {
                    array_splice($trace, 0, $traceOffset);
--- a/Exception/FatalThrowableError.php
+++ b/Exception/FatalThrowableError.php
@@ -36,7 +36,8 @@ class FatalThrowableError extends FatalErrorException
            $e->getCode(),
            $severity,
            $e->getFile(),
-            $e->getLine()
+            $e->getLine(),
+            $e->getPrevious()
        );

        $this->setTrace($e->getTrace());
--- a/Exception/FlattenException.php
+++ b/Exception/FlattenException.php
@@ -53,7 +53,7 @@ class FlattenException
        $e->setStatusCode($statusCode);
        $e->setHeaders($headers);
        $e->setTraceFromException($exception);
-        $e->setClass(get_class($exception));
+        $e->setClass(\get_class($exception));
        $e->setFile($exception->getFile());
        $e->setLine($exception->getLine());

@@ -157,7 +157,7 @@ class FlattenException
        return $this->previous;
    }

-    public function setPrevious(FlattenException $previous)
+    public function setPrevious(self $previous)
    {
        $this->previous = $previous;
    }
@@ -228,9 +228,9 @@ class FlattenException
            if ($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)) {
+            } elseif (\is_object($value)) {
+                $result[$key] = array('object', \get_class($value));
+            } elseif (\is_array($value)) {
                if ($level > 10) {
                    $result[$key] = array('array', '*DEEP NESTED ARRAY*');
                } else {
@@ -238,13 +238,13 @@ class FlattenException
                }
            } elseif (null === $value) {
                $result[$key] = array('null', null);
-            } elseif (is_bool($value)) {
+            } elseif (\is_bool($value)) {
                $result[$key] = array('boolean', $value);
-            } elseif (is_int($value)) {
+            } elseif (\is_int($value)) {
                $result[$key] = array('integer', $value);
-            } elseif (is_float($value)) {
+            } elseif (\is_float($value)) {
                $result[$key] = array('float', $value);
-            } elseif (is_resource($value)) {
+            } elseif (\is_resource($value)) {
                $result[$key] = array('resource', get_resource_type($value));
            } else {
                $result[$key] = array('string', (string) $value);
--- a/Exception/UndefinedFunctionException.php
+++ b/Exception/UndefinedFunctionException.php
@@ -26,6 +26,9 @@ class UndefinedFunctionException extends FatalErrorException
            $previous->getSeverity(),
            $previous->getFile(),
            $previous->getLine(),
+            null,
+            true,
+            null,
            $previous->getPrevious()
        );
        $this->setTrace($previous->getTrace());
--- a/Exception/UndefinedMethodException.php
+++ b/Exception/UndefinedMethodException.php
@@ -26,6 +26,9 @@ class UndefinedMethodException extends FatalErrorException
            $previous->getSeverity(),
            $previous->getFile(),
            $previous->getLine(),
+            null,
+            true,
+            null,
            $previous->getPrevious()
        );
        $this->setTrace($previous->getTrace());
--- a/ExceptionHandler.php
+++ b/ExceptionHandler.php
@@ -40,7 +40,7 @@ class ExceptionHandler
    {
        $this->debug = $debug;
        $this->charset = $charset ?: ini_get('default_charset') ?: 'UTF-8';
-        $this->fileLinkFormat = $fileLinkFormat ?: ini_get('xdebug.file_link_format') ?: get_cfg_var('xdebug.file_link_format');
+        $this->fileLinkFormat = $fileLinkFormat;
    }

    /**
@@ -57,7 +57,7 @@ class ExceptionHandler
        $handler = new static($debug, $charset, $fileLinkFormat);

        $prev = set_exception_handler(array($handler, 'handle'));
-        if (is_array($prev) && $prev[0] instanceof ErrorHandler) {
+        if (\is_array($prev) && $prev[0] instanceof ErrorHandler) {
            restore_exception_handler();
            $prev[0]->setExceptionHandler(array($handler, 'handle'));
        }
@@ -142,7 +142,7 @@ class ExceptionHandler
        $this->caughtBuffer = null;

        try {
-            call_user_func($this->handler, $exception);
+            \call_user_func($this->handler, $exception);
            $this->caughtLength = $caughtLength;
        } catch (\Exception $e) {
            if (!$caughtLength) {
@@ -208,48 +208,54 @@ class ExceptionHandler
                $title = 'Whoops, looks like something went wrong.';
        }

-        $content = '';
-        if ($this->debug) {
-            try {
-                $count = count($exception->getAllPrevious());
-                $total = $count + 1;
-                foreach ($exception->toArray() as $position => $e) {
-                    $ind = $count - $position + 1;
-                    $class = $this->formatClass($e['class']);
-                    $message = nl2br($this->escapeHtml($e['message']));
-                    $content .= sprintf(<<<'EOF'
-                        <div class="trace trace-as-html">
-                            <table class="trace-details">
-                                <thead class="trace-head"><tr><th>
-                                    <h3 class="trace-class">
-                                        <span class="text-muted">(%d/%d)</span>
-                                        <span class="exception_title">%s</span>
-                                    </h3>
-                                    <p class="break-long-words trace-message">%s</p>
-                                </th></tr></thead>
-                                <tbody>
-EOF
-                        , $ind, $total, $class, $message);
-                    foreach ($e['trace'] as $trace) {
-                        $content .= '<tr><td>';
-                        if ($trace['function']) {
-                            $content .= sprintf('at <span class="trace-class">%s</span><span class="trace-type">%s</span><span class="trace-method">%s</span>(<span class="trace-arguments">%s</span>)', $this->formatClass($trace['class']), $trace['type'], $trace['function'], $this->formatArgs($trace['args']));
-                        }
-                        if (isset($trace['file']) && isset($trace['line'])) {
-                            $content .= $this->formatPath($trace['file'], $trace['line']);
-                        }
-                        $content .= "</td></tr>\n";
-                    }
+        if (!$this->debug) {
+            return <<<EOF
+                <div class="container">
+                    <h1>$title</h1>
+                </div>
+EOF;
+        }

-                    $content .= "</tbody>\n</table>\n</div>\n";
-                }
-            } catch (\Exception $e) {
-                // something nasty happened and we cannot throw an exception anymore
-                if ($this->debug) {
-                    $title = sprintf('Exception thrown when handling an exception (%s: %s)', get_class($e), $this->escapeHtml($e->getMessage()));
-                } else {
-                    $title = 'Whoops, looks like something went wrong.';
+        $content = '';
+        try {
+            $count = \count($exception->getAllPrevious());
+            $total = $count + 1;
+            foreach ($exception->toArray() as $position => $e) {
+                $ind = $count - $position + 1;
+                $class = $this->formatClass($e['class']);
+                $message = nl2br($this->escapeHtml($e['message']));
+                $content .= sprintf(<<<'EOF'
+                    <div class="trace trace-as-html">
+                        <table class="trace-details">
+                            <thead class="trace-head"><tr><th>
+                                <h3 class="trace-class">
+                                    <span class="text-muted">(%d/%d)</span>
+                                    <span class="exception_title">%s</span>
+                                </h3>
+                                <p class="break-long-words trace-message">%s</p>
+                            </th></tr></thead>
+                            <tbody>
+EOF
+                    , $ind, $total, $class, $message);
+                foreach ($e['trace'] as $trace) {
+                    $content .= '<tr><td>';
+                    if ($trace['function']) {
+                        $content .= sprintf('at <span class="trace-class">%s</span><span class="trace-type">%s</span><span class="trace-method">%s</span>(<span class="trace-arguments">%s</span>)', $this->formatClass($trace['class']), $trace['type'], $trace['function'], $this->formatArgs($trace['args']));
+                    }
+                    if (isset($trace['file']) && isset($trace['line'])) {
+                        $content .= $this->formatPath($trace['file'], $trace['line']);
+                    }
+                    $content .= "</td></tr>\n";
                }
+
+                $content .= "</tbody>\n</table>\n</div>\n";
+            }
+        } catch (\Exception $e) {
+            // something nasty happened and we cannot throw an exception anymore
+            if ($this->debug) {
+                $title = sprintf('Exception thrown when handling an exception (%s: %s)', \get_class($e), $this->escapeHtml($e->getMessage()));
+            } else {
+                $title = 'Whoops, looks like something went wrong.';
            }
        }

@@ -278,6 +284,14 @@ EOF;
     */
    public function getStylesheet(FlattenException $exception)
    {
+        if (!$this->debug) {
+            return <<<'EOF'
+                body { background-color: #fff; color: #222; font: 16px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; margin: 0; }
+                .container { margin: 30px; max-width: 600px; }
+                h1 { color: #dc3545; font-size: 24px; }
+EOF;
+        }
+
        return <<<'EOF'
            body { background-color: #F9F9F9; color: #222; font: 14px/1.4 Helvetica, Arial, sans-serif; margin: 0; padding-bottom: 45px; }

@@ -355,13 +369,29 @@ EOF;
    private function formatPath($path, $line)
    {
        $file = $this->escapeHtml(preg_match('#[^/\\\\]*+$#', $path, $file) ? $file[0] : $path);
-        $fmt = $this->fileLinkFormat;
+        $fmt = $this->fileLinkFormat ?: ini_get('xdebug.file_link_format') ?: get_cfg_var('xdebug.file_link_format');

-        if ($fmt && $link = is_string($fmt) ? strtr($fmt, array('%f' => $path, '%l' => $line)) : $fmt->format($path, $line)) {
-            return sprintf('<span class="block trace-file-path">in <a href="%s" title="Go to source">%s (line %d)</a></span>', $this->escapeHtml($link), $file, $line);
+        if (!$fmt) {
+            return sprintf('<span class="block trace-file-path">in <a title="%s%3$s"><strong>%s</strong>%s</a></span>', $this->escapeHtml($path), $file, 0 < $line ? ' line '.$line : '');
        }

-        return sprintf('<span class="block trace-file-path">in <a title="%s line %3$d"><strong>%s</strong> (line %d)</a></span>', $this->escapeHtml($path), $file, $line);
+        if (\is_string($fmt)) {
+            $i = strpos($f = $fmt, '&', max(strrpos($f, '%f'), strrpos($f, '%l'))) ?: \strlen($f);
+            $fmt = array(substr($f, 0, $i)) + preg_split('/&([^>]++)>/', substr($f, $i), -1, PREG_SPLIT_DELIM_CAPTURE);
+
+            for ($i = 1; isset($fmt[$i]); ++$i) {
+                if (0 === strpos($path, $k = $fmt[$i++])) {
+                    $path = substr_replace($path, $fmt[$i], 0, \strlen($k));
+                    break;
+                }
+            }
+
+            $link = strtr($fmt[0], array('%f' => $path, '%l' => $line));
+        } else {
+            $link = $fmt->format($path, $line);
+        }
+
+        return sprintf('<span class="block trace-file-path">in <a href="%s" title="Go to source"><strong>%s</string>%s</a></span>', $this->escapeHtml($link), $file, 0 < $line ? ' line '.$line : '');
    }

    /**
@@ -378,7 +408,7 @@ EOF;
            if ('object' === $item[0]) {
                $formattedValue = sprintf('<em>object</em>(%s)', $this->formatClass($item[1]));
            } elseif ('array' === $item[0]) {
-                $formattedValue = sprintf('<em>array</em>(%s)', is_array($item[1]) ? $this->formatArgs($item[1]) : $item[1]);
+                $formattedValue = sprintf('<em>array</em>(%s)', \is_array($item[1]) ? $this->formatArgs($item[1]) : $item[1]);
            } elseif ('null' === $item[0]) {
                $formattedValue = '<em>null</em>';
            } elseif ('boolean' === $item[0]) {
@@ -389,7 +419,7 @@ EOF;
                $formattedValue = str_replace("\n", '', $this->escapeHtml(var_export($item[1], true)));
            }

-            $result[] = is_int($key) ? $formattedValue : sprintf("'%s' => %s", $this->escapeHtml($key), $formattedValue);
+            $result[] = \is_int($key) ? $formattedValue : sprintf("'%s' => %s", $this->escapeHtml($key), $formattedValue);
        }

        return implode(', ', $result);
--- a/FatalErrorHandler/ClassNotFoundFatalErrorHandler.php
+++ b/FatalErrorHandler/ClassNotFoundFatalErrorHandler.php
@@ -11,11 +11,11 @@

 namespace Symfony\Component\Debug\FatalErrorHandler;

-use Symfony\Component\Debug\Exception\ClassNotFoundException;
-use Symfony\Component\Debug\Exception\FatalErrorException;
-use Symfony\Component\Debug\DebugClassLoader;
 use Composer\Autoload\ClassLoader as ComposerClassLoader;
 use Symfony\Component\ClassLoader\ClassLoader as SymfonyClassLoader;
+use Symfony\Component\Debug\DebugClassLoader;
+use Symfony\Component\Debug\Exception\ClassNotFoundException;
+use Symfony\Component\Debug\Exception\FatalErrorException;

 /**
 * ErrorHandler for classes that do not exist.
@@ -29,9 +29,9 @@ class ClassNotFoundFatalErrorHandler implements FatalErrorHandlerInterface
     */
    public function handleError(array $error, FatalErrorException $exception)
    {
-        $messageLen = strlen($error['message']);
+        $messageLen = \strlen($error['message']);
        $notFoundSuffix = '\' not found';
-        $notFoundSuffixLen = strlen($notFoundSuffix);
+        $notFoundSuffixLen = \strlen($notFoundSuffix);
        if ($notFoundSuffixLen > $messageLen) {
            return;
        }
@@ -42,7 +42,7 @@ class ClassNotFoundFatalErrorHandler implements FatalErrorHandlerInterface

        foreach (array('class', 'interface', 'trait') as $typeName) {
            $prefix = ucfirst($typeName).' \'';
-            $prefixLen = strlen($prefix);
+            $prefixLen = \strlen($prefix);
            if (0 !== strpos($error['message'], $prefix)) {
                continue;
            }
@@ -85,7 +85,7 @@ class ClassNotFoundFatalErrorHandler implements FatalErrorHandlerInterface
     */
    private function getClassCandidates($class)
    {
-        if (!is_array($functions = spl_autoload_functions())) {
+        if (!\is_array($functions = spl_autoload_functions())) {
            return array();
        }

@@ -93,14 +93,14 @@ class ClassNotFoundFatalErrorHandler implements FatalErrorHandlerInterface
        $classes = array();

        foreach ($functions as $function) {
-            if (!is_array($function)) {
+            if (!\is_array($function)) {
                continue;
            }
            // get class loaders wrapped by DebugClassLoader
            if ($function[0] instanceof DebugClassLoader) {
                $function = $function[0]->getClassLoader();

-                if (!is_array($function)) {
+                if (!\is_array($function)) {
                    continue;
                }
            }
@@ -133,7 +133,7 @@ class ClassNotFoundFatalErrorHandler implements FatalErrorHandlerInterface
     */
    private function findClassInPath($path, $class, $prefix)
    {
-        if (!$path = realpath($path.'/'.strtr($prefix, '\\_', '//')) ?: realpath($path.'/'.dirname(strtr($prefix, '\\_', '//'))) ?: realpath($path)) {
+        if (!$path = realpath($path.'/'.strtr($prefix, '\\_', '//')) ?: realpath($path.'/'.\dirname(strtr($prefix, '\\_', '//'))) ?: realpath($path)) {
            return array();
        }

@@ -159,7 +159,7 @@ class ClassNotFoundFatalErrorHandler implements FatalErrorHandlerInterface
    {
        $candidates = array(
            // namespaced class
-            $namespacedClass = str_replace(array($path.DIRECTORY_SEPARATOR, '.php', '/'), array('', '', '\\'), $file),
+            $namespacedClass = str_replace(array($path.\DIRECTORY_SEPARATOR, '.php', '/'), array('', '', '\\'), $file),
            // namespaced class (with target dir)
            $prefix.$namespacedClass,
            // namespaced class (with target dir and separator)
--- a/FatalErrorHandler/UndefinedFunctionFatalErrorHandler.php
+++ b/FatalErrorHandler/UndefinedFunctionFatalErrorHandler.php
@@ -11,8 +11,8 @@

 namespace Symfony\Component\Debug\FatalErrorHandler;

-use Symfony\Component\Debug\Exception\UndefinedFunctionException;
 use Symfony\Component\Debug\Exception\FatalErrorException;
+use Symfony\Component\Debug\Exception\UndefinedFunctionException;

 /**
 * ErrorHandler for undefined functions.
@@ -26,9 +26,9 @@ class UndefinedFunctionFatalErrorHandler implements FatalErrorHandlerInterface
     */
    public function handleError(array $error, FatalErrorException $exception)
    {
-        $messageLen = strlen($error['message']);
+        $messageLen = \strlen($error['message']);
        $notFoundSuffix = '()';
-        $notFoundSuffixLen = strlen($notFoundSuffix);
+        $notFoundSuffixLen = \strlen($notFoundSuffix);
        if ($notFoundSuffixLen > $messageLen) {
            return;
        }
@@ -38,7 +38,7 @@ class UndefinedFunctionFatalErrorHandler implements FatalErrorHandlerInterface
        }

        $prefix = 'Call to undefined function ';
-        $prefixLen = strlen($prefix);
+        $prefixLen = \strlen($prefix);
        if (0 !== strpos($error['message'], $prefix)) {
            return;
        }
--- a/FatalErrorHandler/UndefinedMethodFatalErrorHandler.php
+++ b/FatalErrorHandler/UndefinedMethodFatalErrorHandler.php
@@ -44,7 +44,7 @@ class UndefinedMethodFatalErrorHandler implements FatalErrorHandlerInterface
        $candidates = array();
        foreach ($methods as $definedMethodName) {
            $lev = levenshtein($methodName, $definedMethodName);
-            if ($lev <= strlen($methodName) / 3 || false !== strpos($definedMethodName, $methodName)) {
+            if ($lev <= \strlen($methodName) / 3 || false !== strpos($definedMethodName, $methodName)) {
                $candidates[] = $definedMethodName;
            }
        }
--- a/2
+++ b/2
@@ -1,4 +1,4 @@
-Copyright (c) 2004-2017 Fabien Potencier
+Copyright (c) 2004-2018 Fabien Potencier

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
--- a/Resources/ext/tests/001.phpt
+++ b/Resources/ext/tests/001.phpt
@@ -1,7 +1,9 @@
 --TEST--
 Test symfony_zval_info API
 --SKIPIF--
-<?php if (!extension_loaded('symfony_debug')) print 'skip'; ?>
+<?php if (!extension_loaded('symfony_debug')) {
+    echo 'skip';
+} ?>
 --FILE--
 <?php

--- a/Resources/ext/tests/002.phpt
+++ b/Resources/ext/tests/002.phpt
@@ -1,7 +1,9 @@
 --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')) {
+    echo 'skip';
+} ?>
 --FILE--
 <?php

--- a/Resources/ext/tests/002_1.phpt
+++ b/Resources/ext/tests/002_1.phpt
@@ -1,7 +1,9 @@
 --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')) {
+    echo 'skip';
+} ?>
 --FILE--
 <?php

--- a/Resources/ext/tests/003.phpt
+++ b/Resources/ext/tests/003.phpt
@@ -1,7 +1,9 @@
 --TEST--
 Test ErrorHandler in case of fatal error
 --SKIPIF--
-<?php if (!extension_loaded('symfony_debug')) print 'skip'; ?>
+<?php if (!extension_loaded('symfony_debug')) {
+    echo 'skip';
+} ?>
 --FILE--
 <?php

@@ -43,7 +45,7 @@ function foo()
 $handler = ErrorHandler::register();
 $handler->setExceptionHandler('print_r');

-if (function_exists('xdebug_disable')) {
+if (\function_exists('xdebug_disable')) {
    xdebug_disable();
 }

--- a/Tests/DebugClassLoaderTest.php
+++ b/Tests/DebugClassLoaderTest.php
@@ -312,24 +312,21 @@ class DebugClassLoaderTest extends TestCase

    public function testExtendedFinalMethod()
    {
-        set_error_handler(function () { return false; });
-        $e = error_reporting(0);
-        trigger_error('', E_USER_NOTICE);
+        $deprecations = array();
+        set_error_handler(function ($type, $msg) use (&$deprecations) { $deprecations[] = $msg; });
+        $e = error_reporting(E_USER_DEPRECATED);

        class_exists(__NAMESPACE__.'\\Fixtures\\ExtendedFinalMethod', true);

        error_reporting($e);
        restore_error_handler();

-        $lastError = error_get_last();
-        unset($lastError['file'], $lastError['line']);
-
        $xError = array(
-            'type' => E_USER_DEPRECATED,
-            'message' => 'The "Symfony\Component\Debug\Tests\Fixtures\FinalMethod::finalMethod()" method is considered final since version 3.3. It may change without further notice as of its next major version. You should not extend it from "Symfony\Component\Debug\Tests\Fixtures\ExtendedFinalMethod".',
+            'The "Symfony\Component\Debug\Tests\Fixtures\FinalMethod::finalMethod()" method is considered final since version 3.3. It may change without further notice as of its next major version. You should not extend it from "Symfony\Component\Debug\Tests\Fixtures\ExtendedFinalMethod".',
+            'The "Symfony\Component\Debug\Tests\Fixtures\FinalMethod::finalMethod2()" method is considered final. It may change without further notice as of its next major version. You should not extend it from "Symfony\Component\Debug\Tests\Fixtures\ExtendedFinalMethod".',
        );

-        $this->assertSame($xError, $lastError);
+        $this->assertSame($xError, $deprecations);
    }

    public function testExtendedDeprecatedMethodDoesntTriggerAnyNotice()
@@ -361,12 +358,26 @@ class DebugClassLoaderTest extends TestCase
        restore_error_handler();

        $this->assertSame($deprecations, array(
-            'The "Symfony\Component\Debug\Tests\Fixtures\InternalClass" class is considered internal since version 3.4. It may change without further notice. You should not use it from "Test\Symfony\Component\Debug\Tests\ExtendsInternalsParent".',
            'The "Symfony\Component\Debug\Tests\Fixtures\InternalInterface" interface is considered internal. It may change without further notice. You should not use it from "Test\Symfony\Component\Debug\Tests\ExtendsInternalsParent".',
+            'The "Symfony\Component\Debug\Tests\Fixtures\InternalClass" class is considered internal since version 3.4. It may change without further notice. You should not use it from "Test\Symfony\Component\Debug\Tests\ExtendsInternalsParent".',
            'The "Symfony\Component\Debug\Tests\Fixtures\InternalTrait" trait is considered internal. It may change without further notice. You should not use it from "Test\Symfony\Component\Debug\Tests\ExtendsInternals".',
-            'The "Symfony\Component\Debug\Tests\Fixtures\InternalTrait2::internalMethod()" method is considered internal since version 3.4. It may change without further notice. You should not extend it from "Test\Symfony\Component\Debug\Tests\ExtendsInternals".',
+            'The "Symfony\Component\Debug\Tests\Fixtures\InternalClass::internalMethod()" method is considered internal since version 3.4. It may change without further notice. You should not extend it from "Test\Symfony\Component\Debug\Tests\ExtendsInternals".',
        ));
    }
+
+    public function testUseTraitWithInternalMethod()
+    {
+        $deprecations = array();
+        set_error_handler(function ($type, $msg) use (&$deprecations) { $deprecations[] = $msg; });
+        $e = error_reporting(E_USER_DEPRECATED);
+
+        class_exists('Test\\'.__NAMESPACE__.'\\UseTraitWithInternalMethod', true);
+
+        error_reporting($e);
+        restore_error_handler();
+
+        $this->assertSame(array(), $deprecations);
+    }
 }

 class ClassLoader
@@ -420,6 +431,8 @@ class ClassLoader
            }');
        } elseif ('Test\\'.__NAMESPACE__.'\ExtendsInternalsParent' === $class) {
            eval('namespace Test\\'.__NAMESPACE__.'; class ExtendsInternalsParent extends \\'.__NAMESPACE__.'\Fixtures\InternalClass implements \\'.__NAMESPACE__.'\Fixtures\InternalInterface { }');
+        } elseif ('Test\\'.__NAMESPACE__.'\UseTraitWithInternalMethod' === $class) {
+            eval('namespace Test\\'.__NAMESPACE__.'; class UseTraitWithInternalMethod { use \\'.__NAMESPACE__.'\Fixtures\TraitWithInternalMethod; }');
        }
    }
 }
--- a/Tests/ErrorHandlerTest.php
+++ b/Tests/ErrorHandlerTest.php
@@ -35,7 +35,7 @@ class ErrorHandlerTest extends TestCase

            $newHandler = new ErrorHandler();

-            $this->assertSame($newHandler, ErrorHandler::register($newHandler, false));
+            $this->assertSame($handler, ErrorHandler::register($newHandler, false));
            $h = set_error_handler('var_dump');
            restore_error_handler();
            $this->assertSame(array($handler, 'handleError'), $h);
@@ -65,6 +65,30 @@ class ErrorHandlerTest extends TestCase
        }
    }

+    public function testErrorGetLast()
+    {
+        $handler = ErrorHandler::register();
+        $logger = $this->getMockBuilder('Psr\Log\LoggerInterface')->getMock();
+        $handler->setDefaultLogger($logger);
+        $handler->screamAt(E_ALL);
+
+        try {
+            @trigger_error('Hello', E_USER_WARNING);
+            $expected = array(
+                'type' => E_USER_WARNING,
+                'message' => 'Hello',
+                'file' => __FILE__,
+                'line' => __LINE__ - 5,
+            );
+            $this->assertSame($expected, error_get_last());
+        } catch (\Exception $e) {
+            restore_error_handler();
+            restore_exception_handler();
+
+            throw $e;
+        }
+    }
+
    public function testNotice()
    {
        ErrorHandler::register();
@@ -299,6 +323,9 @@ class ErrorHandlerTest extends TestCase
        @$handler->handleError(E_USER_DEPRECATED, 'Foo deprecation', __FILE__, __LINE__, array());
    }

+    /**
+     * @group no-hhvm
+     */
    public function testHandleException()
    {
        try {
@@ -423,6 +450,9 @@ class ErrorHandlerTest extends TestCase
        $handler->setLoggers(array(E_DEPRECATED => array($mockLogger, LogLevel::WARNING)));
    }

+    /**
+     * @group no-hhvm
+     */
    public function testSettingLoggerWhenExceptionIsBuffered()
    {
        $bootLogger = new BufferingLogger();
@@ -442,6 +472,9 @@ class ErrorHandlerTest extends TestCase
        $handler->handleException($exception);
    }

+    /**
+     * @group no-hhvm
+     */
    public function testHandleFatalError()
    {
        try {
@@ -491,7 +524,7 @@ class ErrorHandlerTest extends TestCase

        $handler = new ErrorHandler();
        $handler->setExceptionHandler(function () use (&$args) {
-            $args = func_get_args();
+            $args = \func_get_args();
        });

        $handler->handleException($exception);
@@ -500,6 +533,9 @@ class ErrorHandlerTest extends TestCase
        $this->assertStringStartsWith("Attempted to load class \"Foo\" from the global namespace.\nDid you forget a \"use\" statement", $args[0]->getMessage());
    }

+    /**
+     * @group no-hhvm
+     */
    public function testHandleFatalErrorOnHHVM()
    {
        try {
@@ -526,11 +562,25 @@ class ErrorHandlerTest extends TestCase
                'backtrace' => array(456),
            );

-            call_user_func_array(array($handler, 'handleError'), $error);
+            \call_user_func_array(array($handler, 'handleError'), $error);
            $handler->handleFatalError($error);
        } finally {
            restore_error_handler();
            restore_exception_handler();
        }
    }
+
+    /**
+     * @expectedException \Exception
+     * @group no-hhvm
+     */
+    public function testCustomExceptionHandler()
+    {
+        $handler = new ErrorHandler();
+        $handler->setExceptionHandler(function ($e) use ($handler) {
+            $handler->handleException($e);
+        });
+
+        $handler->handleException(new \Exception());
+    }
 }
--- a/Tests/Exception/FlattenExceptionTest.php
+++ b/Tests/Exception/FlattenExceptionTest.php
@@ -14,19 +14,19 @@ namespace Symfony\Component\Debug\Tests\Exception;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Debug\Exception\FlattenException;
 use Symfony\Component\HttpFoundation\Exception\SuspiciousOperationException;
-use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
-use Symfony\Component\HttpKernel\Exception\MethodNotAllowedHttpException;
-use Symfony\Component\HttpKernel\Exception\UnauthorizedHttpException;
-use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
-use Symfony\Component\HttpKernel\Exception\NotAcceptableHttpException;
-use Symfony\Component\HttpKernel\Exception\ConflictHttpException;
 use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
+use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
+use Symfony\Component\HttpKernel\Exception\ConflictHttpException;
 use Symfony\Component\HttpKernel\Exception\GoneHttpException;
 use Symfony\Component\HttpKernel\Exception\LengthRequiredHttpException;
+use Symfony\Component\HttpKernel\Exception\MethodNotAllowedHttpException;
+use Symfony\Component\HttpKernel\Exception\NotAcceptableHttpException;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Symfony\Component\HttpKernel\Exception\PreconditionFailedHttpException;
 use Symfony\Component\HttpKernel\Exception\PreconditionRequiredHttpException;
 use Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException;
 use Symfony\Component\HttpKernel\Exception\TooManyRequestsHttpException;
+use Symfony\Component\HttpKernel\Exception\UnauthorizedHttpException;
 use Symfony\Component\HttpKernel\Exception\UnsupportedMediaTypeHttpException;

 class FlattenExceptionTest extends TestCase
@@ -111,7 +111,7 @@ class FlattenExceptionTest extends TestCase
    /**
     * @dataProvider flattenDataProvider
     */
-    public function testFlattenHttpException(\Exception $exception, $statusCode)
+    public function testFlattenHttpException(\Exception $exception)
    {
        $flattened = FlattenException::create($exception);
        $flattened2 = FlattenException::create($exception);
@@ -126,7 +126,7 @@ class FlattenExceptionTest extends TestCase
    /**
     * @dataProvider flattenDataProvider
     */
-    public function testPrevious(\Exception $exception, $statusCode)
+    public function testPrevious(\Exception $exception)
    {
        $flattened = FlattenException::create($exception);
        $flattened2 = FlattenException::create($exception);
@@ -173,7 +173,7 @@ class FlattenExceptionTest extends TestCase
    /**
     * @dataProvider flattenDataProvider
     */
-    public function testToArray(\Exception $exception, $statusCode)
+    public function testToArray(\Exception $exception)
    {
        $flattened = FlattenException::create($exception);
        $flattened->setTrace(array(), 'foo.php', 123);
@@ -193,7 +193,7 @@ class FlattenExceptionTest extends TestCase
    public function flattenDataProvider()
    {
        return array(
-            array(new \Exception('test', 123), 500),
+            array(new \Exception('test', 123)),
        );
    }

@@ -236,7 +236,7 @@ class FlattenExceptionTest extends TestCase
        $this->assertSame(array('object', 'stdClass'), $array[$i++]);
        $this->assertSame(array('object', 'Symfony\Component\HttpKernel\Exception\NotFoundHttpException'), $array[$i++]);
        $this->assertSame(array('incomplete-object', 'BogusTestClass'), $array[$i++]);
-        $this->assertSame(array('resource', defined('HHVM_VERSION') ? 'Directory' : 'stream'), $array[$i++]);
+        $this->assertSame(array('resource', \defined('HHVM_VERSION') ? 'Directory' : 'stream'), $array[$i++]);
        $this->assertSame(array('resource', 'stream'), $array[$i++]);

        $args = $array[$i++];
@@ -261,6 +261,7 @@ class FlattenExceptionTest extends TestCase

    public function testRecursionInArguments()
    {
+        $a = null;
        $a = array('foo', array(2, &$a));
        $exception = $this->createException($a);

--- a/Tests/ExceptionHandlerTest.php
+++ b/Tests/ExceptionHandlerTest.php
@@ -12,10 +12,10 @@
 namespace Symfony\Component\Debug\Tests;

 use PHPUnit\Framework\TestCase;
-use Symfony\Component\Debug\ExceptionHandler;
 use Symfony\Component\Debug\Exception\OutOfMemoryException;
-use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+use Symfony\Component\Debug\ExceptionHandler;
 use Symfony\Component\HttpKernel\Exception\MethodNotAllowedHttpException;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;

 require_once __DIR__.'/HeaderMock.php';

--- a/Tests/FatalErrorHandler/ClassNotFoundFatalErrorHandlerTest.php
+++ b/Tests/FatalErrorHandler/ClassNotFoundFatalErrorHandlerTest.php
@@ -11,18 +11,18 @@

 namespace Symfony\Component\Debug\Tests\FatalErrorHandler;

+use Composer\Autoload\ClassLoader as ComposerClassLoader;
 use PHPUnit\Framework\TestCase;
+use Symfony\Component\Debug\DebugClassLoader;
 use Symfony\Component\Debug\Exception\FatalErrorException;
 use Symfony\Component\Debug\FatalErrorHandler\ClassNotFoundFatalErrorHandler;
-use Symfony\Component\Debug\DebugClassLoader;
-use Composer\Autoload\ClassLoader as ComposerClassLoader;

 class ClassNotFoundFatalErrorHandlerTest extends TestCase
 {
    public static function setUpBeforeClass()
    {
        foreach (spl_autoload_functions() as $function) {
-            if (!is_array($function)) {
+            if (!\is_array($function)) {
                continue;
            }

@@ -32,7 +32,7 @@ class ClassNotFoundFatalErrorHandlerTest extends TestCase
            }

            if ($function[0] instanceof ComposerClassLoader) {
-                $function[0]->add('Symfony_Component_Debug_Tests_Fixtures', dirname(dirname(dirname(dirname(dirname(__DIR__))))));
+                $function[0]->add('Symfony_Component_Debug_Tests_Fixtures', \dirname(\dirname(\dirname(\dirname(\dirname(__DIR__))))));
                break;
            }
        }
--- a/Tests/FatalErrorHandler/UndefinedMethodFatalErrorHandlerTest.php
+++ b/Tests/FatalErrorHandler/UndefinedMethodFatalErrorHandlerTest.php
@@ -64,10 +64,10 @@ class UndefinedMethodFatalErrorHandlerTest extends TestCase
            ),
            array(
                array(
-                  'type' => 1,
-                  'message' => 'Call to undefined method class@anonymous::test()',
-                  'file' => '/home/possum/work/symfony/test.php',
-                  'line' => 11,
+                    'type' => 1,
+                    'message' => 'Call to undefined method class@anonymous::test()',
+                    'file' => '/home/possum/work/symfony/test.php',
+                    'line' => 11,
                ),
                'Attempted to call an undefined method named "test" of class "class@anonymous".',
            ),
--- a/Tests/Fixtures/ExtendedFinalMethod.php
+++ b/Tests/Fixtures/ExtendedFinalMethod.php
@@ -4,6 +4,8 @@ namespace Symfony\Component\Debug\Tests\Fixtures;

 class ExtendedFinalMethod extends FinalMethod
 {
+    use FinalMethod2Trait;
+
    /**
     * {@inheritdoc}
     */
--- a/Tests/Fixtures/FinalMethod.php
+++ b/Tests/Fixtures/FinalMethod.php
@@ -11,6 +11,13 @@ class FinalMethod
    {
    }

+    /**
+     * @final
+     */
+    public function finalMethod2()
+    {
+    }
+
    public function anotherMethod()
    {
    }
--- a/Tests/Fixtures/FinalMethod2Trait.php
+++ b/Tests/Fixtures/FinalMethod2Trait.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace Symfony\Component\Debug\Tests\Fixtures;
+
+trait FinalMethod2Trait
+{
+    public function finalMethod2()
+    {
+    }
+}
--- a/Tests/Fixtures/TraitWithInternalMethod.php
+++ b/Tests/Fixtures/TraitWithInternalMethod.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Symfony\Component\Debug\Tests\Fixtures;
+
+trait TraitWithInternalMethod
+{
+    /**
+     * @internal
+     */
+    public function foo()
+    {
+    }
+}
--- a/Tests/HeaderMock.php
+++ b/Tests/HeaderMock.php
@@ -27,12 +27,12 @@ function testHeader()
 {
    static $headers = array();

-    if (!$h = func_get_args()) {
+    if (!$h = \func_get_args()) {
        $h = $headers;
        $headers = array();

        return $h;
    }

-    $headers[] = func_get_args();
+    $headers[] = \func_get_args();
 }
--- a/Tests/phpt/debug_class_loader.phpt
+++ b/Tests/phpt/debug_class_loader.phpt
@@ -0,0 +1,27 @@
+--TEST--
+Test DebugClassLoader with previously loaded parents
+--FILE--
+<?php
+
+namespace Symfony\Component\Debug\Tests\Fixtures;
+
+use Symfony\Component\Debug\DebugClassLoader;
+
+$vendor = __DIR__;
+while (!file_exists($vendor.'/vendor')) {
+    $vendor = \dirname($vendor);
+}
+require $vendor.'/vendor/autoload.php';
+
+class_exists(FinalMethod::class);
+
+set_error_handler(function ($type, $msg) { echo $msg, "\n"; });
+
+DebugClassLoader::enable();
+
+class_exists(ExtendedFinalMethod::class);
+
+?>
+--EXPECTF--
+The "Symfony\Component\Debug\Tests\Fixtures\FinalMethod::finalMethod()" method is considered final since version 3.3. It may change without further notice as of its next major version. You should not extend it from "Symfony\Component\Debug\Tests\Fixtures\ExtendedFinalMethod".
+The "Symfony\Component\Debug\Tests\Fixtures\FinalMethod::finalMethod2()" method is considered final. It may change without further notice as of its next major version. You should not extend it from "Symfony\Component\Debug\Tests\Fixtures\ExtendedFinalMethod".
--- a/Tests/phpt/decorate_exception_hander.phpt
+++ b/Tests/phpt/decorate_exception_hander.phpt
@@ -0,0 +1,47 @@
+--TEST--
+Test catching fatal errors when handlers are nested
+--INI--
+display_errors=0
+--FILE--
+<?php
+
+namespace Symfony\Component\Debug;
+
+$vendor = __DIR__;
+while (!file_exists($vendor.'/vendor')) {
+    $vendor = \dirname($vendor);
+}
+require $vendor.'/vendor/autoload.php';
+
+set_error_handler('var_dump');
+set_exception_handler('var_dump');
+
+ErrorHandler::register(null, false);
+
+if (true) {
+    class foo extends missing
+    {
+    }
+}
+
+?>
+--EXPECTF--
+object(Symfony\Component\Debug\Exception\ClassNotFoundException)#%d (8) {
+  ["message":protected]=>
+  string(131) "Attempted to load class "missing" from namespace "Symfony\Component\Debug".
+Did you forget a "use" statement for another namespace?"
+  ["string":"Exception":private]=>
+  string(0) ""
+  ["code":protected]=>
+  int(0)
+  ["file":protected]=>
+  string(%d) "%s"
+  ["line":protected]=>
+  int(%d)
+  ["trace":"Exception":private]=>
+  array(%d) {%A}
+  ["previous":"Exception":private]=>
+  NULL
+  ["severity":protected]=>
+  int(1)
+}
--- a/Tests/phpt/exception_rethrown.phpt
+++ b/Tests/phpt/exception_rethrown.phpt
@@ -0,0 +1,35 @@
+--TEST--
+Test rethrowing in custom exception handler
+--FILE--
+<?php
+
+namespace Symfony\Component\Debug;
+
+$vendor = __DIR__;
+while (!file_exists($vendor.'/vendor')) {
+    $vendor = \dirname($vendor);
+}
+require $vendor.'/vendor/autoload.php';
+
+if (true) {
+    class TestLogger extends \Psr\Log\AbstractLogger
+    {
+        public function log($level, $message, array $context = array())
+        {
+            echo $message, "\n";
+        }
+    }
+}
+
+set_exception_handler(function ($e) { echo 123; throw $e; });
+ErrorHandler::register()->setDefaultLogger(new TestLogger());
+ini_set('display_errors', 1);
+
+throw new \Exception('foo');
+?>
+--EXPECTF--
+Uncaught Exception: foo
+123
+Fatal error: Uncaught %s:25
+Stack trace:
+%a
--- a/Tests/phpt/fatal_with_nested_handlers.phpt
+++ b/Tests/phpt/fatal_with_nested_handlers.phpt
@@ -0,0 +1,42 @@
+--TEST--
+Test catching fatal errors when handlers are nested
+--FILE--
+<?php
+
+namespace Symfony\Component\Debug;
+
+$vendor = __DIR__;
+while (!file_exists($vendor.'/vendor')) {
+    $vendor = \dirname($vendor);
+}
+require $vendor.'/vendor/autoload.php';
+
+Debug::enable();
+ini_set('display_errors', 0);
+
+$eHandler = set_error_handler('var_dump');
+$xHandler = set_exception_handler('var_dump');
+
+var_dump(array(
+    $eHandler[0] === $xHandler[0] ? 'Error and exception handlers do match' : 'Error and exception handlers are different',
+));
+
+$eHandler[0]->setExceptionHandler('print_r');
+
+if (true) {
+    class Broken implements \Serializable
+    {
+    }
+}
+
+?>
+--EXPECTF--
+array(1) {
+  [0]=>
+  string(37) "Error and exception handlers do match"
+}
+object(Symfony\Component\Debug\Exception\FatalErrorException)#%d (%d) {
+  ["message":protected]=>
+  string(199) "Error: Class Symfony\Component\Debug\Broken contains 2 abstract methods and must therefore be declared abstract or implement the remaining methods (Serializable::serialize, Serializable::unserialize)"
+%a
+}