From a8796b0bd2799ad3ac67e3dab663c3d4bbb2a3d0 Mon Sep 17 00:00:00 2001
From: tophf <tophf@gmx.com>
Date: Tue, 12 Sep 2017 12:10:43 +0300
Subject: [PATCH] prevent race condition in getStyles before dbExec.initialized

fixes #184
---
 background/storage.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/background/storage.js b/background/storage.js
index c3d30b4a..389dd365 100644
--- a/background/storage.js
+++ b/background/storage.js
@@ -23,7 +23,8 @@ var cachedStyles = {
   urlDomains: new Map(), // getDomain() results for 100 last checked urls
   needTransitionPatch: new Map(), // FF bug workaround
   mutex: {
-    inProgress: false,   // while getStyles() is reading IndexedDB all subsequent calls
+    inProgress: true,    // while getStyles() is reading IndexedDB all subsequent calls
+                         // (initially 'true' to prevent rogue getStyles before dbExec.initialized)
     onDone: [],          // to getStyles() are queued and resolved when the first one finishes
   },
 };
@@ -92,6 +93,7 @@ dbExec.initialized = false;
 // (FF may block localStorage depending on its privacy options)
 do {
   const done = () => {
+    cachedStyles.mutex.inProgress = false;
     getStyles().then(() => {
       dbExec.initialized = true;
       window.dispatchEvent(new Event('storageReady'));