bug #19651 [HttpKernel] Fix HttpCache validation HTTP method (tgalopin)

This PR was merged into the 2.7 branch.

Discussion
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[HttpKernel] Fix HttpCache validation HTTP method

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #19582
| License       | MIT
| Doc PR        | -

Commits
-------

1a8a8af [HttpKernel] Fix HttpCache validation HTTP method

Author: fabpot

HttpCache/HttpCache.php

@@ -374,7 +374,9 @@ protected function validate(Request $request, Response $entry, $catch = false)
         $subRequest = clone $request;
 
         // send no head requests because we want content
-        $subRequest->setMethod('GET');
+        if ('HEAD' === $request->getMethod()) {
+            $subRequest->setMethod('GET');
+        }
 
         // add our cached last-modified validator
         $subRequest->headers->set('if_modified_since', $entry->headers->get('Last-Modified'));
@@ -435,7 +437,9 @@ protected function fetch(Request $request, $catch = false)
         $subRequest = clone $request;
 
         // send no head requests because we want content
-        $subRequest->setMethod('GET');
+        if ('HEAD' === $request->getMethod()) {
+            $subRequest->setMethod('GET');
+        }
 
         // avoid that the backend sends no content
         $subRequest->headers->remove('if_modified_since');

Tests/HttpCache/HttpCacheTest.php

@@ -799,6 +799,21 @@ public function testValidatesCachedResponsesWithLastModifiedAndNoFreshnessInform
         $this->assertTraceNotContains('miss');
     }
 
+    public function testValidatesCachedResponsesUseSameHttpMethod()
+    {
+        $test = $this;
+
+        $this->setNextResponse(200, array(), 'Hello World', function ($request, $response) use ($test) {
+            $test->assertSame('OPTIONS', $request->getMethod());
+        });
+
+        // build initial request
+        $this->request('OPTIONS', '/');
+
+        // build subsequent request
+        $this->request('OPTIONS', '/');
+    }
+
     public function testValidatesCachedResponsesWithETagAndNoFreshnessInformation()
     {
         $this->setNextResponse(200, array(), 'Hello World', function ($request, $response) {