Aprhont - Adding cookie-prefix, as config option, and into cookie methods

Summary: Cookie-prefix should fix phabricator instances where x.com and x.y.com have conflicting cookie names

Test Plan: Pushed branch to dev.phab.example.com, logged into phab.example.com and into dev.phab.example.com.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7979

src/aphront/AphrontRequest.php

@@ -273,11 +273,26 @@ final class AphrontRequest {
     return $this->validateCSRF();
   }
 
+  final public function setCookiePrefix($prefix) {
+    $this->cookiePrefix = $prefix;
+    return $this;
+  }
+
+  final private function getPrefixedCookieName($name) {
+    if (strlen($this->cookiePrefix)) {
+      return $this->cookiePrefix.'_'.$name;
+    } else {
+      return $name;
+    }
+  }
+
   final public function getCookie($name, $default = null) {
+    $name = $this->getPrefixedCookieName($name);
     return idx($_COOKIE, $name, $default);
   }
 
   final public function clearCookie($name) {
+    $name = $this->getPrefixedCookieName($name);
     $this->setCookie($name, '', time() - (60 * 60 * 24 * 30));
     unset($_COOKIE[$name]);
   }
@@ -342,6 +357,7 @@ final class AphrontRequest {
       $expire = time() + (60 * 60 * 24 * 365 * 5);
     }
 
+    $name = $this->getPrefixedCookieName($name);
 
     if (php_sapi_name() == 'cli') {
       // Do nothing, to avoid triggering "Cannot modify header information"

src/aphront/configuration/AphrontDefaultApplicationConfiguration.php

@@ -107,9 +107,12 @@ class AphrontDefaultApplicationConfiguration
 
     $data += $parser->parseQueryString(idx($_SERVER, 'QUERY_STRING', ''));
 
+    $cookie_prefix = PhabricatorEnv::getEnvConfig('phabricator.cookie-prefix');
+
     $request = new AphrontRequest($this->getHost(), $this->getPath());
     $request->setRequestData($data);
     $request->setApplicationConfiguration($this);
+    $request->setCookiePrefix($cookie_prefix);
 
     return $request;
   }

src/applications/config/option/PhabricatorCoreConfigOptions.php

@@ -76,6 +76,16 @@ final class PhabricatorCoreConfigOptions
         ->addExample('America/Chicago', pht('US Central (CDT)'))
         ->addExample('America/Boise', pht('US Mountain (MDT)'))
         ->addExample('America/Los_Angeles', pht('US West (PDT)')),
+      $this->newOption('phabricator.cookie-prefix', 'string', null)
+        ->setSummary(
+          pht("Set a string Phabricator should use to prefix ".
+              "cookie names"))
+        ->setDescription(
+          pht(
+            "Cookies set for x.com are also sent for y.x.com. Assuming ".
+            "Phabricator instances are running on both domains, this will ".
+            "create a collision preventing you from logging in."))
+        ->addExample('dev', pht('Prefix cookie with "dev"')),
       $this->newOption('phabricator.show-beta-applications', 'bool', false)
         ->setBoolOptions(
           array(