Merge branch '2.8' into 3.2

* 2.8:
  don't keep internal state between parser runs
  Add \Traversable typehint to phpdoc
  [ExpressionLanguage] Avoid dependency on ctype
  [Debug] Fix php notice
  [VarDumper] Relax tests to adapt for php 7.1rc4

src/Symfony/Component/Debug/DebugClassLoader.php

@@ -151,7 +151,7 @@ class DebugClassLoader
 
         $exists = class_exists($class, false) || interface_exists($class, false) || trait_exists($class, false);
 
-        if ('\\' === $class[0]) {
+        if ($class && '\\' === $class[0]) {
             $class = substr($class, 1);
         }
 

src/Symfony/Component/ExpressionLanguage/Lexer.php

@@ -45,7 +45,7 @@ class Lexer
             if (preg_match('/[0-9]+(?:\.[0-9]+)?/A', $expression, $match, null, $cursor)) {
                 // numbers
                 $number = (float) $match[0];  // floats
-                if (ctype_digit($match[0]) && $number <= PHP_INT_MAX) {
+                if (preg_match('/^[0-9]+$/', $match[0]) && $number <= PHP_INT_MAX) {
                     $number = (int) $match[0]; // integers lower than the maximum
                 }
                 $tokens[] = new Token(Token::NUMBER_TYPE, $number, $cursor + 1);

src/Symfony/Component/Form/DataMapperInterface.php

@@ -19,8 +19,8 @@ interface DataMapperInterface
     /**
      * Maps properties of some data to a list of forms.
      *
-     * @param mixed           $data  Structured data
-     * @param FormInterface[] $forms A list of {@link FormInterface} instances
+     * @param mixed                        $data  Structured data
+     * @param FormInterface[]|\Traversable $forms A list of {@link FormInterface} instances
      *
      * @throws Exception\UnexpectedTypeException if the type of the data parameter is not supported.
      */
@@ -29,8 +29,8 @@ interface DataMapperInterface
     /**
      * Maps the data of a list of forms into the properties of some data.
      *
-     * @param FormInterface[] $forms A list of {@link FormInterface} instances
-     * @param mixed           $data  Structured data
+     * @param FormInterface[]|\Traversable $forms A list of {@link FormInterface} instances
+     * @param mixed                        $data  Structured data
      *
      * @throws Exception\UnexpectedTypeException if the type of the data parameter is not supported.
      */

src/Symfony/Component/VarDumper/Tests/CliDumperTest.php

@@ -293,9 +293,7 @@ stream resource {@{$ref}
         : } catch (%s \$e) {
       }
       %sCliDumperTest.php:{$line}: {
-        :         }
-        :     };'),
-        : ));
+%A
       }
     }
   }

src/Symfony/Component/Yaml/Parser.php

@@ -87,23 +87,51 @@ class Parser
         if (false === preg_match('//u', $value)) {
             throw new ParseException('The YAML value does not appear to be valid UTF-8.');
         }
-        $this->currentLineNb = -1;
-        $this->currentLine = '';
-        $value = $this->cleanup($value);
-        $this->lines = explode("\n", $value);
 
-        if (null === $this->totalNumberOfLines) {
-            $this->totalNumberOfLines = count($this->lines);
-        }
+        $this->refs = array();
+
+        $mbEncoding = null;
+        $e = null;
+        $data = null;
 
         if (2 /* MB_OVERLOAD_STRING */ & (int) ini_get('mbstring.func_overload')) {
             $mbEncoding = mb_internal_encoding();
             mb_internal_encoding('UTF-8');
         }
 
+        try {
+            $data = $this->doParse($value, $flags);
+        } catch (\Exception $e) {
+        } catch (\Throwable $e) {
+        }
+
+        if (null !== $mbEncoding) {
+            mb_internal_encoding($mbEncoding);
+        }
+
+        if (null !== $e) {
+            throw $e;
+        }
+
+        return $data;
+    }
+
+    private function doParse($value, $flags)
+    {
+        $this->currentLineNb = -1;
+        $this->currentLine = '';
+        $value = $this->cleanup($value);
+        $this->lines = explode("\n", $value);
+        $this->locallySkippedLineNumbers = array();
+
+        if (null === $this->totalNumberOfLines) {
+            $this->totalNumberOfLines = count($this->lines);
+        }
+
         $data = array();
         $context = null;
         $allowOverwrite = false;
+
         while ($this->moveToNextLine()) {
             if ($this->isCurrentLineEmpty()) {
                 continue;
@@ -279,10 +307,6 @@ class Parser
                         throw $e;
                     }
 
-                    if (isset($mbEncoding)) {
-                        mb_internal_encoding($mbEncoding);
-                    }
-
                     return $value;
                 }
 
@@ -290,10 +314,6 @@ class Parser
             }
         }
 
-        if (isset($mbEncoding)) {
-            mb_internal_encoding($mbEncoding);
-        }
-
         if (Yaml::PARSE_OBJECT_FOR_MAP & $flags && !is_object($data) && 'mapping' === $context) {
             $object = new \stdClass();
 
@@ -322,7 +342,7 @@ class Parser
         $parser = new self($offset, $this->totalNumberOfLines, $skippedLineNumbers);
         $parser->refs = &$this->refs;
 
-        return $parser->parse($yaml, $flags);
+        return $parser->doParse($yaml, $flags);
     }
 
     /**

src/Symfony/Component/Yaml/Tests/ParserTest.php

@@ -1490,6 +1490,27 @@ EOT;
 
         $this->assertEquals($trickyVal, $arrayFromYaml);
     }
+
+    /**
+     * @expectedException \Symfony\Component\Yaml\Exception\ParseException
+     * @expectedExceptionMessage Reference "foo" does not exist at line 2
+     */
+    public function testParserCleansUpReferencesBetweenRuns()
+    {
+        $yaml = <<<YAML
+foo: &foo
+    baz: foobar
+bar:
+    <<: *foo
+YAML;
+        $this->parser->parse($yaml);
+
+        $yaml = <<<YAML
+bar:
+    <<: *foo
+YAML;
+        $this->parser->parse($yaml);
+    }
 }
 
 class B