bug symfony#14635 [HttpKernel] Handle an array vary header in the http cache store (jakzal)

This PR was merged into the 2.3 branch.

Discussion
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[HttpKernel] Handle an array vary header in the http cache store

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | symfony#12118
| License       | MIT
| Doc PR        | -

Commits
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5930800 [HttpKernel] Handle an array vary header in the http cache store

Author: fabpot

src/Symfony/Component/HttpKernel/HttpCache/Store.php

@@ -127,7 +127,7 @@ public function lookup(Request $request)
         // find a cached entry that matches the request.
         $match = null;
         foreach ($entries as $entry) {
-            if ($this->requestsMatch(isset($entry[1]['vary'][0]) ? $entry[1]['vary'][0] : '', $request->headers->all(), $entry[0])) {
+            if ($this->requestsMatch(isset($entry[1]['vary'][0]) ? implode(', ', $entry[1]['vary']) : '', $request->headers->all(), $entry[0])) {
                 $match = $entry;
 
                 break;

src/Symfony/Component/HttpKernel/Tests/HttpCache/StoreTest.php

@@ -168,6 +168,16 @@ public function testDoesNotReturnEntriesThatVaryWithLookup()
         $this->assertNull($this->store->lookup($req2));
     }
 
+    public function testDoesNotReturnEntriesThatSlightlyVaryWithLookup()
+    {
+        $req1 = Request::create('/test', 'get', array(), array(), array(), array('HTTP_FOO' => 'Foo', 'HTTP_BAR' => 'Bar'));
+        $req2 = Request::create('/test', 'get', array(), array(), array(), array('HTTP_FOO' => 'Foo', 'HTTP_BAR' => 'Bam'));
+        $res = new Response('test', 200, array('Vary' => array('Foo', 'Bar')));
+        $this->store->write($req1, $res);
+
+        $this->assertNull($this->store->lookup($req2));
+    }
+
     public function testStoresMultipleResponsesForEachVaryCombination()
     {
         $req1 = Request::create('/test', 'get', array(), array(), array(), array('HTTP_FOO' => 'Foo', 'HTTP_BAR' => 'Bar'));