bug #18907 [Routing] Fix the annotation loader taking a class constan…

…t as a beginning of a class name (jakzal, nicolas-grekas)

This PR was merged into the 2.3 branch.

Discussion
----------

[Routing] Fix the annotation loader taking a class constant as a beginning of a class name

| Q             | A
| ------------- | ---
| Branch?       | 2.3
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #18633
| License       | MIT
| Doc PR        | -

Code copy/pasted from ClassMapGenerator.php

Commits
-------

8d4f35d [Routing] Finish annotation loader taking a class constant as a beginning of a class name
43c7f9b [Routing] Fix the annotation loader taking a class constant as a beginning of a class name

src/Symfony/Component/Routing/Loader/AnnotationFileLoader.php

@@ -112,7 +112,24 @@ protected function findClass($file)
             }
 
             if (T_CLASS === $token[0]) {
-                $class = true;
+                // Skip usage of ::class constant
+                $isClassConstant = false;
+                for ($j = $i - 1; $j > 0; --$j) {
+                    if (!isset($tokens[$j][1])) {
+                        break;
+                    }
+
+                    if (T_DOUBLE_COLON === $tokens[$j][0]) {
+                        $isClassConstant = true;
+                        break;
+                    } elseif (!in_array($tokens[$j][0], array(T_WHITESPACE, T_DOC_COMMENT, T_COMMENT))) {
+                        break;
+                    }
+                }
+
+                if (!$isClassConstant) {
+                    $class = true;
+                }
             }
 
             if (T_NAMESPACE === $token[0]) {

src/Symfony/Component/Routing/Tests/Fixtures/AnnotatedClasses/FooTrait.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace Symfony\Component\Routing\Tests\Fixtures\AnnotatedClasses;
+
+trait FooTrait
+{
+    public function doBar()
+    {
+        $baz = self::class;
+        if (true) {
+        }
+    }
+}

src/Symfony/Component/Routing/Tests/Loader/AnnotationFileLoaderTest.php

@@ -35,6 +35,16 @@ public function testLoad()
         $this->loader->load(__DIR__.'/../Fixtures/AnnotatedClasses/FooClass.php');
     }
 
+    /**
+     * @requires PHP 5.4
+     */
+    public function testLoadTraitWithClassConstant()
+    {
+        $this->reader->expects($this->never())->method('getClassAnnotation');
+
+        $this->loader->load(__DIR__.'/../Fixtures/AnnotatedClasses/FooTrait.php');
+    }
+
     /**
      * @requires PHP 5.6
      */