bug #23757 [Yaml] parse inlined tags without values (xabbuh)

This PR was merged into the 4.0-dev branch.

Discussion
----------

[Yaml] parse inlined tags without values

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

Commits
-------

3bb0a3f [Yaml] parse inlined tags without values

src/Symfony/Component/Yaml/Inline.php

@@ -644,7 +644,7 @@ private static function parseTag($value, &$i, $flags)
             return;
         }
 
-        $tagLength = strcspn($value, " \t\n", $i + 1);
+        $tagLength = strcspn($value, " \t\n[]{},", $i + 1);
         $tag = substr($value, $i + 1, $tagLength);
 
         $nextOffset = $i + $tagLength + 1;

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

@@ -14,6 +14,7 @@
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Yaml\Exception\ParseException;
 use Symfony\Component\Yaml\Inline;
+use Symfony\Component\Yaml\Tag\TaggedValue;
 use Symfony\Component\Yaml\Yaml;
 
 class InlineTest extends TestCase
@@ -695,4 +696,40 @@ public function getNotPhpCompatibleMappingKeyData()
             'float' => array('{0.25: "foo"}', array('0.25' => 'foo')),
         );
     }
+
+    public function testTagWithoutValueInSequence()
+    {
+        $value = Inline::parse('[!foo]', Yaml::PARSE_CUSTOM_TAGS);
+
+        $this->assertInstanceOf(TaggedValue::class, $value[0]);
+        $this->assertSame('foo', $value[0]->getTag());
+        $this->assertSame('', $value[0]->getValue());
+    }
+
+    public function testTagWithEmptyValueInSequence()
+    {
+        $value = Inline::parse('[!foo ""]', Yaml::PARSE_CUSTOM_TAGS);
+
+        $this->assertInstanceOf(TaggedValue::class, $value[0]);
+        $this->assertSame('foo', $value[0]->getTag());
+        $this->assertSame('', $value[0]->getValue());
+    }
+
+    public function testTagWithoutValueInMapping()
+    {
+        $value = Inline::parse('{foo: !bar}', Yaml::PARSE_CUSTOM_TAGS);
+
+        $this->assertInstanceOf(TaggedValue::class, $value['foo']);
+        $this->assertSame('bar', $value['foo']->getTag());
+        $this->assertSame('', $value['foo']->getValue());
+    }
+
+    public function testTagWithEmptyValueInMapping()
+    {
+        $value = Inline::parse('{foo: !bar ""}', Yaml::PARSE_CUSTOM_TAGS);
+
+        $this->assertInstanceOf(TaggedValue::class, $value['foo']);
+        $this->assertSame('bar', $value['foo']->getTag());
+        $this->assertSame('', $value['foo']->getValue());
+    }
 }