From 6f12c6eb0ec14c971e5b3b84338511b0c56477a9 Mon Sep 17 00:00:00 2001
From: mickadoo <michaeldevery@gmail.com>
Date: Tue, 14 Mar 2017 10:57:56 +0000
Subject: [PATCH] CRM-20254: add cache buster string for custom CSS and improve
 query string generation (duplicated from original PR which was to the wrong
 branch)

---
 CRM/Core/Resources.php                   | 28 +++++++++++++++--
 tests/phpunit/CRM/Core/ResourcesTest.php | 40 ++++++++++++++++++++++++
 2 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/CRM/Core/Resources.php b/CRM/Core/Resources.php
index cb46b981bd..bccbefa845 100644
--- a/CRM/Core/Resources.php
+++ b/CRM/Core/Resources.php
@@ -500,7 +500,7 @@ class CRM_Core_Resources {
       $file = '';
     }
     if ($addCacheCode) {
-      $file .= '?r=' . $this->getCacheCode();
+      $file = $this->addCacheCode($file);
     }
     // TODO consider caching results
     $base = $this->paths->hasVariable($ext)
@@ -643,7 +643,8 @@ class CRM_Core_Resources {
       // Load custom or core css
       $config = CRM_Core_Config::singleton();
       if (!empty($config->customCSSURL)) {
-        $this->addStyleUrl($config->customCSSURL, 99, $region);
+        $customCSSURL = $this->addCacheCode($config->customCSSURL);
+        $this->addStyleUrl($customCSSURL, 99, $region);
       }
       if (!Civi::settings()->get('disable_core_css')) {
         $this->addStyleFile('civicrm', 'css/civicrm.css', -99, $region);
@@ -881,4 +882,27 @@ class CRM_Core_Resources {
     }
   }
 
+  /**
+   * @param string $url
+   * @return string
+   */
+  public function addCacheCode($url) {
+    parse_str(parse_url($url, PHP_URL_QUERY), $queryParts);
+    $existing = isset($queryParts['r']) ? $queryParts['r'] : NULL;
+    $latest = $this->cacheCode;
+
+    if ($existing) {
+      if ($existing === $latest) {
+        return $url; // no need to update
+      }
+      else {
+        return str_replace('r=' . $existing, 'r=' . $latest, $url);
+      }
+    }
+
+    $operator = empty($queryParts) ? '?' : '&';
+
+    return $url . $operator . 'r=' . $latest;
+  }
+
 }
diff --git a/tests/phpunit/CRM/Core/ResourcesTest.php b/tests/phpunit/CRM/Core/ResourcesTest.php
index ea0d74ca01..693ad2039a 100644
--- a/tests/phpunit/CRM/Core/ResourcesTest.php
+++ b/tests/phpunit/CRM/Core/ResourcesTest.php
@@ -41,6 +41,11 @@ class CRM_Core_ResourcesTest extends CiviUnitTestCase {
    */
   protected $mapper;
 
+  /**
+   * @var string for testing cache buster generation
+   */
+  protected $cacheBusterString = 'xBkdk3';
+
   protected $originalRequest;
   protected $originalGet;
 
@@ -348,4 +353,39 @@ class CRM_Core_ResourcesTest extends CiviUnitTestCase {
     return array($basedir, $c, $mapper);
   }
 
+  /**
+   * @param string $url
+   * @param string $expected
+   *
+   * @dataProvider urlForCacheCodeProvider
+   */
+  public function testAddingCacheCode($url, $expected) {
+    $resources = CRM_Core_Resources::singleton();
+    $this->assertEquals($expected, $resources->addCacheCode($url));
+  }
+
+  /**
+   * @return array
+   */
+  public function urlForCacheCodeProvider() {
+    return array(
+      array(
+        'http://www.civicrm.org',
+        'http://www.civicrm.org?r=' . $this->cacheBusterString,
+      ),
+      array(
+        'www.civicrm.org/custom.css?foo=bar',
+        'www.civicrm.org/custom.css?foo=bar&r=' . $this->cacheBusterString,
+      ),
+      array(
+        'civicrm.org/custom.css?r=old&foo=bar',
+        'civicrm.org/custom.css?r=' . $this->cacheBusterString . '&foo=bar',
+      ),
+      array(
+        'civicrm.org/custom.css?car=blue&foo=bar',
+        'civicrm.org/custom.css?car=blue&foo=bar&r=' . $this->cacheBusterString,
+      ),
+    );
+  }
+
 }
-- 
2.25.1