bug #20725 [HttpKernel] Fix annotation cache warmer with failing or missing classes (nicolas-grekas)

This PR was merged into the 3.2 branch.

Discussion
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[HttpKernel] Fix annotation cache warmer with failing or missing classes

| Q             | A
| ------------- | ---
| Branch?       | 3.2
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #20720
| License       | MIT
| Doc PR        | -

Commits
-------

dcf9fbb [HttpKernel] Fix annotation cache warmer with failing or missing classes

src/Symfony/Bundle/FrameworkBundle/CacheWarmer/AnnotationsCacheWarmer.php

@@ -66,9 +66,19 @@ class AnnotationsCacheWarmer implements CacheWarmerInterface
 
         $arrayPool = new ArrayAdapter(0, false);
         $reader = new CachedReader($this->annotationReader, new DoctrineProvider($arrayPool));
+        $throwingAutoloader = function ($class) { throw new \ReflectionException(sprintf('Class %s does not exist', $class)); };
+        spl_autoload_register($throwingAutoloader);
 
-        foreach ($annotatedClasses as $class) {
-            $this->readAllComponents($reader, $class);
+        try {
+            foreach ($annotatedClasses as $class) {
+                try {
+                    $this->readAllComponents($reader, $class);
+                } catch (\ReflectionException $e) {
+                    // ignore failing reflection
+                }
+            }
+        } finally {
+            spl_autoload_unregister($throwingAutoloader);
         }
 
         $values = $arrayPool->getValues();

src/Symfony/Component/HttpKernel/DependencyInjection/AddClassesToCachePass.php

@@ -101,7 +101,7 @@ class AddClassesToCachePass implements CompilerPassInterface
             }
 
             if (is_array($function) && $function[0] instanceof ClassLoader) {
-                $classes += $function[0]->getClassMap();
+                $classes += array_filter($function[0]->getClassMap());
             }
         }