Revert "NEW Add better HTTP cache-control manipulation (silverstripe#…

…8086)"

This reverts commit 2b49540.

Conflicts:
	_config/config.yml
	docs/en/02_Developer_Guides/08_Performance/02_HTTP_Cache_Headers.md
	docs/en/04_Changelogs/3.7.0.md
	tests/control/HTTPTest.php

_config/config.yml

@@ -13,19 +13,13 @@ MySQLDatabase:
   collation: utf8_general_ci
 HTTP:
   cache_control:
-    no-cache: "true"
-    no-store: "true"
+    max-age: 0
     must-revalidate: "true"
-  vary: "X-Forwarded-Protocol"
+    no-transform: "true"
+  vary: "Cookie, X-Forwarded-Protocol, User-Agent, Accept"
 LeftAndMain:
   dependencies:
     versionProvider: %$SilverStripeVersionProvider
 SilverStripeVersionProvider:
   modules:
     silverstripe/framework: Framework
----
-Only:
-  environment: dev
----
-HTTP:
-  disable_http_cache: true

api/RSSFeed.php

@@ -204,7 +204,10 @@ public function outputToBrowser() {
 			HTTP::register_etag($this->etag);
 		}
 
-		$response->addHeader("Content-Type", "application/rss+xml; charset=utf-8");
+		if(!headers_sent()) {
+			HTTP::add_cache_headers();
+			$response->addHeader("Content-Type", "application/rss+xml; charset=utf-8");
+		}
 
 		Config::inst()->update('SSViewer', 'source_file_comments', $prevState);
 

control/Controller.php

@@ -169,7 +169,10 @@ public function handleRequest(SS_HTTPRequest $request, DataModel $model) {
 			$response->setBody($body);
 		}
 
+
 		ContentNegotiator::process($response);
+		HTTP::add_cache_headers($response);
+
 		$this->popCurrent();
 		return $response;
 	}
@@ -499,7 +502,7 @@ public function redirect($url, $code=302) {
 	 */
 	public function redirectBack() {
 		// Don't cache the redirect back ever
-		HTTPCacheControl::singleton()->disableCache(true);
+		HTTP::set_cache_age(0);
 
 		$url = null;
 

control/Director.php

@@ -386,14 +386,7 @@ protected static function handleRequest(SS_HTTPRequest $request, Session $sessio
 					} catch(SS_HTTPResponse_Exception $responseException) {
 						$result = $responseException->getResponse();
 					}
-					// Ensure cache headers are added
-					if ($result instanceof SS_HTTPResponse) {
-						HTTP::add_cache_headers($result);
-						return $result;
-					}
-					if(!is_object($result)) {
-						return $result;
-					}
+					if(!is_object($result) || $result instanceof SS_HTTPResponse) return $result;
 
 					user_error("Bad result from url " . $request->getURL() . " handled by " .
 						get_class($controllerObj)." controller: ".get_class($result), E_USER_WARNING);

control/FlushRequestFilter.php

@@ -18,9 +18,6 @@ public function preRequest(SS_HTTPRequest $request, Session $session, DataModel
 	}
 
 	public function postRequest(SS_HTTPRequest $request, SS_HTTPResponse $response, DataModel $model) {
-		if(array_key_exists('flush', $request->getVars())) {
-			HTTPCacheControl::singleton()->disableCache(true);
-		}
 		return true;
 	}