bug #19704 [DependencyInjection] PhpDumper::isFrozen inconsistency (allflame)

This PR was submitted for the master branch but it was merged into the 2.7 branch instead (closes #19704).

Discussion
----------

[DependencyInjection] PhpDumper::isFrozen inconsistency

| Q             | A
| ------------- | ---
| Branch?       | 3.1
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | yes
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |
There is a bug (from my prespective) regarding cached container generated by the PhpDumper. ProjectServiceContainer::isFrozen call will be forwarded to the Container::isFrozen method which relies on instance of the parameter bag property. In the cached ProjectServiceContainer parameter bag is undefined afetr intialization hence calls to the isFrozen will result in false unless getParameterBag will be called and then calls to isFrozen will return true onwards.
This can actually break some compatibility, although it's a bug from my prespective from the very beginning

Commits
-------

7c0a62c [DependencyInjection] PhpDumper::isFrozen inconsistency

Author: fabpot

src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php

@@ -144,6 +144,7 @@ public function dump(array $options = array())
         if ($this->container->isFrozen()) {
             $code .= $this->addFrozenConstructor();
             $code .= $this->addFrozenCompile();
+            $code .= $this->addIsFrozenMethod();
         } else {
             $code .= $this->addConstructor();
         }
@@ -957,6 +958,26 @@ public function compile()
         throw new LogicException('You cannot compile a dumped frozen container.');
     }
 
+EOF;
+    }
+
+    /**
+     * Adds the isFrozen method for a frozen container.
+     *
+     * @return string
+     */
+    private function addIsFrozenMethod()
+    {
+        return <<<EOF
+
+    /*{$this->docStar}
+     * {@inheritdoc}
+     */
+    public function isFrozen()
+    {
+        return true;
+    }
+
 EOF;
     }
 

src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services10.php

@@ -46,6 +46,14 @@ public function compile()
         throw new LogicException('You cannot compile a dumped frozen container.');
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function isFrozen()
+    {
+        return true;
+    }
+
     /**
      * Gets the 'test' service.
      *

src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services12.php

@@ -50,6 +50,14 @@ public function compile()
         throw new LogicException('You cannot compile a dumped frozen container.');
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function isFrozen()
+    {
+        return true;
+    }
+
     /**
      * Gets the 'test' service.
      *

src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services13.php

@@ -44,6 +44,14 @@ public function compile()
         throw new LogicException('You cannot compile a dumped frozen container.');
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function isFrozen()
+    {
+        return true;
+    }
+
     /**
      * Gets the 'bar' service.
      *

src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_compiled.php

@@ -62,6 +62,14 @@ public function compile()
         throw new LogicException('You cannot compile a dumped frozen container.');
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function isFrozen()
+    {
+        return true;
+    }
+
     /**
      * Gets the 'bar' service.
      *