symfony
diff --git a/‎src/Symfony/Component/Yaml/Parser.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Yaml/Parser.php
+11-2Lines changed: 11 additions & 2 deletions b/‎src/Symfony/Component/Yaml/Parser.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Yaml/Parser.php
+11-2Lines changed: 11 additions & 2 deletions
diff --git a/‎src/Symfony/Component/Yaml/Tests/ParserTest.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Yaml/Tests/ParserTest.php
+38-5Lines changed: 38 additions & 5 deletions b/‎src/Symfony/Component/Yaml/Tests/ParserTest.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Yaml/Tests/ParserTest.php
+38-5Lines changed: 38 additions & 5 deletions
@@ -402,7 +402,7 @@ private function doParse($value, $flags)
                     throw new ParseException('Multiple documents are not supported.', $this->currentLineNb + 1, $this->currentLine, $this->filename);
                 }
 
-                if (isset($this->currentLine[1]) && '?' === $this->currentLine[0] && ' ' === $this->currentLine[1]) {
+                if ($deprecatedUsage = (isset($this->currentLine[1]) && '?' === $this->currentLine[0] && ' ' === $this->currentLine[1])) {
                     @trigger_error($this->getDeprecationMessage('Starting an unquoted string with a question mark followed by a space is deprecated since Symfony 3.3 and will throw \Symfony\Component\Yaml\Exception\ParseException in 4.0.'), E_USER_DEPRECATED);
                 }
 
@@ -421,7 +421,16 @@ private function doParse($value, $flags)
                 }
 
                 // try to parse the value as a multi-line string as a last resort
-                if (0 === $this->currentLineNb && !$this->isNextLineIndented()) {
+                if (0 === $this->currentLineNb && 1 < $this->totalNumberOfLines) {
+                    // If the indentation is not consistent at offset 0, it is to be considered as a ParseError
+                    if (0 === $this->offset && !$deprecatedUsage) {
+                        foreach ($this->lines as $line) {
+                            if (rtrim($line) !== trim($line)) {
+                                throw new ParseException('Unable to parse.', $this->getRealCurrentLineNb() + 1, $this->currentLine, $this->filename);
+                            }
+                        }
+                    }
+
                     $previousLineWasNewline = false;
                     $previousLineWasTerminatedWithBackslash = false;
                     $value = '';
 
@@ -812,15 +812,37 @@ public function testNonStringFollowedByCommentEmbeddedInMapping()
         $this->assertSame($expected, $this->parser->parse($yaml));
     }
 
+    public function getParseExceptionNotAffectedMultiLineStringLastResortParsing() {
+        $tests = array();
+
+        $yaml = <<<'EOT'
+a
+    b:
+EOT;
+        $tests['parse error on first line'] = array($yaml);
+
+        $yaml = <<<'EOT'
+a
+
+b
+    c:
+EOT;
+        $tests['parse error due to inconsistent indentation'] = array($yaml);
+
+        $yaml = <<<'EOT'
+ &  *  !  |  >  '  "  %  @  ` #, { asd a;sdasd }-@^qw3
+EOT;
+        $tests['symfony/symfony/issues/22967#issuecomment-322067742'] = array($yaml);
+
+        return $tests;
+    }
+
     /**
+     * @dataProvider getParseExceptionNotAffectedMultiLineStringLastResortParsing
      * @expectedException \Symfony\Component\Yaml\Exception\ParseException
      */
-    public function testMultiLineStringLastResortParsingOnlyAffectSameIndentationLevel()
+    public function testParseExceptionNotAffectedByMultiLineStringLastResortParsing($yaml)
     {
-        $yaml = <<<'EOT'
-parse
-    error:
-EOT;
         $this->parser->parse($yaml);
     }
 
@@ -837,6 +859,17 @@ public function testMultiLineStringLastResortParsing()
         );
 
         $this->assertSame($expected, $this->parser->parse($yaml));
+
+        $yaml = <<<'EOT'
+a:
+    b
+       c
+EOT;
+        $expected = array(
+            'a' => 'b c',
+        );
+
+        $this->assertSame($expected, $this->parser->parse($yaml));
     }
 
     /**