bug #39267 [Yaml] fix lexing backslashes in single quoted strings (xabbuh)

This PR was merged into the 4.4 branch.

Discussion
----------

[Yaml] fix lexing backslashes in single quoted strings

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | Fix #39265
| License       | MIT
| Doc PR        |

Commits
-------

668732305a fix lexing backslashes in single quoted strings

Author: xabbuh

Parser.php

@@ -1170,7 +1170,9 @@ private function lexInlineQuotedString(int &$cursor = 0): string
             for (; \strlen($this->currentLine) > $cursor; ++$cursor) {
                 switch ($this->currentLine[$cursor]) {
                     case '\\':
-                        if (isset($this->currentLine[++$cursor])) {
+                        if ("'" === $quotation) {
+                            $value .= '\\';
+                        } elseif (isset($this->currentLine[++$cursor])) {
                             $value .= '\\'.$this->currentLine[$cursor];
                         }
 

Tests/ParserTest.php

@@ -1618,6 +1618,11 @@ public function escapedQuotationCharactersInQuotedStrings()
         ];
     }
 
+    public function testBackslashInSingleQuotedString()
+    {
+        $this->assertSame(['foo' => 'bar\\'], $this->parser->parse("foo: 'bar\'"));
+    }
+
     public function testParseMultiLineString()
     {
         $this->assertEquals("foo bar\nbaz", $this->parser->parse("foo\nbar\n\nbaz"));