bug symfony#11244 [HttpFoundation] Remove body-related headers when sending the response, if body is empty (SimonSimCity)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes symfony#11244).

Discussion
----------

[HttpFoundation] Remove body-related headers when sending the response, if body is empty

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

I've updated the implementation for informational and 204 or 304 responses. They will now, as they have no content, not return headers like `content-type` or `content-length`.

I'm unsure about `content-length` - we could also set it hardcoded to zero ... but I thought, that (because the specs say that it just can't have a response-body) the system should not return anything here.

Commits
-------

9dbe89d [HttpFoundation] Remove content-related headers if content is empty

Author: fabpot

src/Symfony/Component/HttpFoundation/Response.php

@@ -209,36 +209,42 @@ public function prepare(Request $request)
 
         if ($this->isInformational() || in_array($this->statusCode, array(204, 304))) {
             $this->setContent(null);
-        }
-
-        // Content-type based on the Request
-        if (!$headers->has('Content-Type')) {
-            $format = $request->getRequestFormat();
-            if (null !== $format && $mimeType = $request->getMimeType($format)) {
-                $headers->set('Content-Type', $mimeType);
+            $headers->remove('Content-Type');
+            $headers->remove('Content-Length');
+        } else {
+            // Content-type based on the Request
+            if (!$headers->has('Content-Type')) {
+                $format = $request->getRequestFormat();
+                if (null !== $format && $mimeType = $request->getMimeType($format)) {
+                    $headers->set('Content-Type', $mimeType);
+                }
             }
-        }
 
-        // Fix Content-Type
-        $charset = $this->charset ?: 'UTF-8';
-        if (!$headers->has('Content-Type')) {
-            $headers->set('Content-Type', 'text/html; charset='.$charset);
-        } elseif (0 === stripos($headers->get('Content-Type'), 'text/') && false === stripos($headers->get('Content-Type'), 'charset')) {
-            // add the charset
-            $headers->set('Content-Type', $headers->get('Content-Type').'; charset='.$charset);
-        }
+            // Fix Content-Type
+            $charset = $this->charset ?: 'UTF-8';
+            if (!$headers->has('Content-Type')) {
+                $headers->set('Content-Type', 'text/html; charset=' . $charset);
+            } elseif (0 === stripos($headers->get('Content-Type'), 'text/') && false === stripos(
+                    $headers->get('Content-Type'),
+                    'charset'
+                )
+            ) {
+                // add the charset
+                $headers->set('Content-Type', $headers->get('Content-Type') . '; charset=' . $charset);
+            }
 
-        // Fix Content-Length
-        if ($headers->has('Transfer-Encoding')) {
-            $headers->remove('Content-Length');
-        }
+            // Fix Content-Length
+            if ($headers->has('Transfer-Encoding')) {
+                $headers->remove('Content-Length');
+            }
 
-        if ($request->isMethod('HEAD')) {
-            // cf. RFC2616 14.13
-            $length = $headers->get('Content-Length');
-            $this->setContent(null);
-            if ($length) {
-                $headers->set('Content-Length', $length);
+            if ($request->isMethod('HEAD')) {
+                // cf. RFC2616 14.13
+                $length = $headers->get('Content-Length');
+                $this->setContent(null);
+                if ($length) {
+                    $headers->set('Content-Length', $length);
+                }
             }
         }
 

src/Symfony/Component/HttpFoundation/Tests/ResponseTest.php

@@ -374,6 +374,8 @@ public function testPrepareRemovesContentForHeadRequests()
         $response->prepare($request);
 
         $this->assertEquals('', $response->getContent());
+        $this->assertFalse($response->headers->has('Content-Type'));
+        $this->assertFalse($response->headers->has('Content-Length'));
     }
 
     public function testPrepareSetsPragmaOnHttp10Only()