Inline.php

@@ -583,7 +583,8 @@ private static function evaluateScalar(string $scalar, int $flags, array $refere
                         return;
                     case 0 === strpos($scalar, '!php/const'):
                         if (self::$constantSupport) {
-                            if (defined($const = self::parseScalar(substr($scalar, 11)))) {
+                            $i = 0;
+                            if (defined($const = self::parseScalar(substr($scalar, 11), 0, null, $i, false))) {
                                 return constant($const);
                             }
 

Parser.php

@@ -521,7 +521,27 @@ private function getNextEmbedBlock(int $indentation = null, bool $inSequence = f
         }
 
         if (null === $indentation) {
-            $newIndent = $this->getCurrentLineIndentation();
+            $newIndent = null;
+            $movements = 0;
+
+            do {
+                $EOF = false;
+
+                // empty and comment-like lines do not influence the indentation depth
+                if ($this->isCurrentLineEmpty() || $this->isCurrentLineComment()) {
+                    $EOF = !$this->moveToNextLine();
+
+                    if (!$EOF) {
+                        ++$movements;
+                    }
+                } else {
+                    $newIndent = $this->getCurrentLineIndentation();
+                }
+            } while (!$EOF && null === $newIndent);
+
+            for ($i = 0; $i < $movements; ++$i) {
+                $this->moveToPreviousLine();
+            }
 
             $unindentedEmbedBlock = $this->isStringUnIndentedCollectionItem();
 
@@ -535,6 +555,8 @@ private function getNextEmbedBlock(int $indentation = null, bool $inSequence = f
         $data = array();
         if ($this->getCurrentLineIndentation() >= $newIndent) {
             $data[] = substr($this->currentLine, $newIndent);
+        } elseif ($this->isCurrentLineEmpty() || $this->isCurrentLineComment()) {
+            $data[] = $this->currentLine;
         } else {
             $this->moveToPreviousLine();
 
@@ -851,19 +873,25 @@ private function parseBlockScalar(string $style, string $chomping = '', int $ind
     private function isNextLineIndented(): bool
     {
         $currentIndentation = $this->getCurrentLineIndentation();
-        $EOF = !$this->moveToNextLine();
+        $movements = 0;
 
-        while (!$EOF && $this->isCurrentLineEmpty()) {
+        do {
             $EOF = !$this->moveToNextLine();
-        }
+
+            if (!$EOF) {
+                ++$movements;
+            }
+        } while (!$EOF && ($this->isCurrentLineEmpty() || $this->isCurrentLineComment()));
 
         if ($EOF) {
             return false;
         }
 
         $ret = $this->getCurrentLineIndentation() > $currentIndentation;
 
-        $this->moveToPreviousLine();
+        for ($i = 0; $i < $movements; ++$i) {
+            $this->moveToPreviousLine();
+        }
 
         return $ret;
     }
@@ -952,19 +980,25 @@ private function cleanup(string $value): string
     private function isNextLineUnIndentedCollection(): bool
     {
         $currentIndentation = $this->getCurrentLineIndentation();
-        $notEOF = $this->moveToNextLine();
+        $movements = 0;
 
-        while ($notEOF && $this->isCurrentLineEmpty()) {
-            $notEOF = $this->moveToNextLine();
-        }
+        do {
+            $EOF = !$this->moveToNextLine();
+
+            if (!$EOF) {
+                ++$movements;
+            }
+        } while (!$EOF && ($this->isCurrentLineEmpty() || $this->isCurrentLineComment()));
 
-        if (false === $notEOF) {
+        if ($EOF) {
             return false;
         }
 
         $ret = $this->getCurrentLineIndentation() === $currentIndentation && $this->isStringUnIndentedCollectionItem();
 
-        $this->moveToPreviousLine();
+        for ($i = 0; $i < $movements; ++$i) {
+            $this->moveToPreviousLine();
+        }
 
         return $ret;
     }

Tests/InlineTest.php

@@ -59,6 +59,7 @@ public function getTestsForParsePhpConstants()
             array('!php/const PHP_INT_MAX', PHP_INT_MAX),
             array('[!php/const PHP_INT_MAX]', array(PHP_INT_MAX)),
             array('{ foo: !php/const PHP_INT_MAX }', array('foo' => PHP_INT_MAX)),
+            array('!php/const NULL', null),
         );
     }
 

Tests/ParserTest.php

@@ -1932,6 +1932,80 @@ public function testEvalRefException()
 EOE;
         $this->parser->parse($yaml);
     }
+
+    /**
+     * @dataProvider indentedMappingData
+     */
+    public function testParseIndentedMappings($yaml, $expected)
+    {
+        $this->assertSame($expected, $this->parser->parse($yaml));
+    }
+
+    public function indentedMappingData()
+    {
+        $tests = array();
+
+        $yaml = <<<YAML
+foo:
+  - bar: "foobar"
+    # A comment
+    baz: "foobaz"
+YAML;
+        $expected = array(
+            'foo' => array(
+                array(
+                    'bar' => 'foobar',
+                    'baz' => 'foobaz',
+                ),
+            ),
+        );
+        $tests['comment line is first line in indented block'] = array($yaml, $expected);
+
+        $yaml = <<<YAML
+foo:
+    - bar:
+        # comment
+        baz: [1, 2, 3]
+YAML;
+        $expected = array(
+            'foo' => array(
+                array(
+                    'bar' => array(
+                        'baz' => array(1, 2, 3),
+                    ),
+                ),
+            ),
+        );
+        $tests['mapping value on new line starting with a comment line'] = array($yaml, $expected);
+
+        $yaml = <<<YAML
+foo:
+  -
+    bar: foobar
+YAML;
+        $expected = array(
+            'foo' => array(
+                array(
+                    'bar' => 'foobar',
+                ),
+            ),
+        );
+        $tests['mapping in sequence starting on a new line'] = array($yaml, $expected);
+
+        $yaml = <<<YAML
+foo:
+
+    bar: baz
+YAML;
+        $expected = array(
+            'foo' => array(
+                'bar' => 'baz',
+            ),
+        );
+        $tests['blank line at the beginning of an indented mapping value'] = array($yaml, $expected);
+
+        return $tests;
+    }
 }
 
 class B