From 44bc92dfdd8f7dcb3345c15bdaeae3a68a667743 Mon Sep 17 00:00:00 2001
From: Andrew Nicols <andrew@nicols.co.uk>
Date: Wed, 13 Feb 2019 07:37:03 +0800
Subject: [PATCH] MDL-64835 JS: Stop using the jsrev in the jsrevPrefix

We only use the jsrevPrefix to determine if the cache should be
invalidated, but the prefix that we were using is based on the new
jsrev.

For example, the jsrevPrefix will be:

    hash(wwwroot + '/ + config.jsrev) + '/jsrev'

Where config.jsrev is the _current_ (new) jsrev.

As a result when searching for the jsrev used to store the data which is
currently in the storage cache, no key is returned, and we instead set
an 'initial' value and the cache is not cleared

This patch changes the jsrevPrefix to be:

    hash(wwwroot) + '/jsrev'

Since the wwwroot does not change, the key remains static for the
current site. As a result, when the jsrev is bumped via a Moodle cache
purge, we are able to correctly fetch the old jsrev from the cache,
determine that the jsrev has changed, and purge the cache.
---
 lib/amd/build/storagewrapper.min.js | 2 +-
 lib/amd/src/storagewrapper.js       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/amd/build/storagewrapper.min.js b/lib/amd/build/storagewrapper.min.js
index 01fd0c64179..edc052e7304 100644
--- a/lib/amd/build/storagewrapper.min.js
+++ b/lib/amd/build/storagewrapper.min.js
@@ -1 +1 @@
-define(["core/config"],function(a){var b=function(b){this.storage=b,this.supported=this.detectSupport(),this.hashSource=a.wwwroot+"/"+a.jsrev,this.hash=this.hashString(this.hashSource),this.prefix=this.hash+"/",this.jsrevPrefix=this.hash+"/jsrev"};return b.prototype.detectSupport=function(){if(a.jsrev==-1)return!1;if("undefined"==typeof this.storage)return!1;var b="test";try{return null!==this.storage&&(this.storage.setItem(b,"1"),this.storage.removeItem(b),!0)}catch(c){return!1}},b.prototype.prefixKey=function(a){return this.prefix+a},b.prototype.validateCache=function(){var b=this.storage.getItem(this.jsrevPrefix);if(null===b)return void this.storage.setItem(this.jsrevPrefix,a.jsrev);var c=a.jsrev;c!=b&&(this.storage.clear(),this.storage.setItem(this.jsrevPrefix,a.jsrev))},b.prototype.hashString=function(a){var b,c,d,e=0;if(0===a.length)return e;for(b=0,d=a.length;b<d;b++)c=a.charCodeAt(b),e=(e<<5)-e+c,e|=0;return e},b.prototype.get=function(a){return!!this.supported&&(this.validateCache(),a=this.prefixKey(a),this.storage.getItem(a))},b.prototype.set=function(a,b){if(!this.supported)return!1;this.validateCache(),a=this.prefixKey(a);try{this.storage.setItem(a,b)}catch(c){return!1}return!0},b});
\ No newline at end of file
+define(["core/config"],function(a){var b=function(b){this.storage=b,this.supported=this.detectSupport(),this.hashSource=a.wwwroot+"/"+a.jsrev,this.hash=this.hashString(this.hashSource),this.prefix=this.hash+"/",this.jsrevPrefix=this.hashString(a.wwwroot)+"/jsrev"};return b.prototype.detectSupport=function(){if(a.jsrev==-1)return!1;if("undefined"==typeof this.storage)return!1;var b="test";try{return null!==this.storage&&(this.storage.setItem(b,"1"),this.storage.removeItem(b),!0)}catch(c){return!1}},b.prototype.prefixKey=function(a){return this.prefix+a},b.prototype.validateCache=function(){var b=this.storage.getItem(this.jsrevPrefix);if(null===b)return void this.storage.setItem(this.jsrevPrefix,a.jsrev);var c=a.jsrev;c!=b&&(this.storage.clear(),this.storage.setItem(this.jsrevPrefix,a.jsrev))},b.prototype.hashString=function(a){var b,c,d,e=0;if(0===a.length)return e;for(b=0,d=a.length;b<d;b++)c=a.charCodeAt(b),e=(e<<5)-e+c,e|=0;return e},b.prototype.get=function(a){return!!this.supported&&(this.validateCache(),a=this.prefixKey(a),this.storage.getItem(a))},b.prototype.set=function(a,b){if(!this.supported)return!1;this.validateCache(),a=this.prefixKey(a);try{this.storage.setItem(a,b)}catch(c){return!1}return!0},b});
\ No newline at end of file
diff --git a/lib/amd/src/storagewrapper.js b/lib/amd/src/storagewrapper.js
index 7f7f3e62c06..d9d114728f2 100644
--- a/lib/amd/src/storagewrapper.js
+++ b/lib/amd/src/storagewrapper.js
@@ -35,7 +35,7 @@ define(['core/config'], function(config) {
         this.hashSource = config.wwwroot + '/' + config.jsrev;
         this.hash = this.hashString(this.hashSource);
         this.prefix = this.hash + '/';
-        this.jsrevPrefix = this.hash + '/jsrev';
+        this.jsrevPrefix = this.hashString(config.wwwroot) + '/jsrev';
     };
 
     /**