bug symfony#25787 Yaml parser regression with comments and non-strings (alexpott)

This PR was squashed before being merged into the 3.4 branch (closes symfony#25787).

Discussion
----------

Yaml parser regression with comments and non-strings

| Q             | A
| ------------- | ---
| Branch?       | 3.3 <!-- see below -->
| Bug fix?      | yes
| New feature?  | no <!-- don't forget to update src/**/CHANGELOG.md files -->
| BC breaks?    | no
| Deprecations? | no <!-- don't forget to update UPGRADE-*.md files -->
| Tests pass?   | no
| Fixed tickets | symfony#25786
| License       | MIT
| Doc PR        | symfony/symfony-docs#... <!--highly recommended for new features-->

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Commits
-------

a7e2a49 Yaml parser regression with comments and non-strings

Author: xabbuh

src/Symfony/Component/Yaml/Parser.php

@@ -422,54 +422,39 @@ private function doParse($value, $flags)
 
                 // try to parse the value as a multi-line string as a last resort
                 if (0 === $this->currentLineNb) {
-                    $parseError = false;
                     $previousLineWasNewline = false;
                     $previousLineWasTerminatedWithBackslash = false;
                     $value = '';
 
                     foreach ($this->lines as $line) {
-                        try {
-                            if (isset($line[0]) && ('"' === $line[0] || "'" === $line[0])) {
-                                $parsedLine = $line;
-                            } else {
-                                $parsedLine = Inline::parse($line, $flags, $this->refs);
-                            }
-
-                            if (!is_string($parsedLine)) {
-                                $parseError = true;
-                                break;
-                            }
-
-                            if ('' === trim($parsedLine)) {
-                                $value .= "\n";
-                            } elseif (!$previousLineWasNewline && !$previousLineWasTerminatedWithBackslash) {
-                                $value .= ' ';
-                            }
+                        if ('' === trim($line)) {
+                            $value .= "\n";
+                        } elseif (!$previousLineWasNewline && !$previousLineWasTerminatedWithBackslash) {
+                            $value .= ' ';
+                        }
 
-                            if ('' !== trim($parsedLine) && '\\' === substr($parsedLine, -1)) {
-                                $value .= ltrim(substr($parsedLine, 0, -1));
-                            } elseif ('' !== trim($parsedLine)) {
-                                $value .= trim($parsedLine);
-                            }
+                        if ('' !== trim($line) && '\\' === substr($line, -1)) {
+                            $value .= ltrim(substr($line, 0, -1));
+                        } elseif ('' !== trim($line)) {
+                            $value .= trim($line);
+                        }
 
-                            if ('' === trim($parsedLine)) {
-                                $previousLineWasNewline = true;
-                                $previousLineWasTerminatedWithBackslash = false;
-                            } elseif ('\\' === substr($parsedLine, -1)) {
-                                $previousLineWasNewline = false;
-                                $previousLineWasTerminatedWithBackslash = true;
-                            } else {
-                                $previousLineWasNewline = false;
-                                $previousLineWasTerminatedWithBackslash = false;
-                            }
-                        } catch (ParseException $e) {
-                            $parseError = true;
-                            break;
+                        if ('' === trim($line)) {
+                            $previousLineWasNewline = true;
+                            $previousLineWasTerminatedWithBackslash = false;
+                        } elseif ('\\' === substr($line, -1)) {
+                            $previousLineWasNewline = false;
+                            $previousLineWasTerminatedWithBackslash = true;
+                        } else {
+                            $previousLineWasNewline = false;
+                            $previousLineWasTerminatedWithBackslash = false;
                         }
                     }
 
-                    if (!$parseError) {
+                    try {
                         return Inline::parse(trim($value));
+                    } catch (ParseException $e) {
+                        // fall-through to the ParseException thrown below
                     }
                 }
 

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

@@ -791,6 +791,42 @@ public function testSequenceFollowedByCommentEmbeddedInMapping()
         $this->assertSame($expected, $this->parser->parse($yaml));
     }
 
+    public function testNonStringFollowedByCommentEmbeddedInMapping()
+    {
+        $yaml = <<<'EOT'
+a:
+    b:
+        {}
+# comment
+    d:
+        1.1
+# another comment
+EOT;
+        $expected = array(
+            'a' => array(
+                'b' => array(),
+                'd' => 1.1,
+            ),
+        );
+
+        $this->assertSame($expected, $this->parser->parse($yaml));
+    }
+
+    public function testMultiLineStringLastResortParsing()
+    {
+        $yaml = <<<'EOT'
+test:
+  You can have things that don't look like strings here
+  true
+  yes you can
+EOT;
+        $expected = array(
+            'test' => 'You can have things that don\'t look like strings here true yes you can',
+        );
+
+        $this->assertSame($expected, $this->parser->parse($yaml));
+    }
+
     /**
      * @expectedException \Symfony\Component\Yaml\Exception\ParseException
      */