bug #13953 [Translation][MoFileLoader] fixed load empty translation. (aitboudad)

This PR was merged into the 2.3 branch.

Discussion
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[Translation][MoFileLoader] fixed load empty translation.

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Fixed tickets  | #13547
| Tests pass?   | yes
| License       | MIT

see https://www.gnu.org/software/gettext/manual/html_node/MO-Files.html

![selection_003](https://cloud.githubusercontent.com/assets/1753742/6690874/fcf04ef6-ccba-11e4-83a4-4f50188709c5.png)

Commits
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22f5a73 [Translation][MoFileLoader] fixed load empty translation.

src/Symfony/Component/Translation/Loader/MoFileLoader.php

@@ -137,6 +137,10 @@ class MoFileLoader extends ArrayLoader implements LoaderInterface
             $length = $this->readLong($stream, $isBigEndian);
             $offset = $this->readLong($stream, $isBigEndian);
 
+            if ($length < 1) {
+                continue;
+            }
+
             fseek($stream, $offset);
             $translated = fread($stream, $length);
 

src/Symfony/Component/Translation/Tests/Loader/MoFileLoaderTest.php

@@ -57,4 +57,15 @@ class MoFileLoaderTest extends \PHPUnit_Framework_TestCase
         $resource = __DIR__.'/../fixtures/empty.mo';
         $loader->load($resource, 'en', 'domain1');
     }
+
+    public function testLoadEmptyTranslation()
+    {
+        $loader = new MoFileLoader();
+        $resource = __DIR__.'/../fixtures/empty-translation.mo';
+        $catalogue = $loader->load($resource, 'en', 'message');
+
+        $this->assertEquals(array(), $catalogue->all('message'));
+        $this->assertEquals('en', $catalogue->getLocale());
+        $this->assertEquals(array(new FileResource($resource)), $catalogue->getResources());
+    }
 }