Add ability to deactivate workaround for the bug 1763420

Author: piroor

webextensions/background/background.js

@@ -191,6 +191,7 @@ async function notifyReadyToSidebars() {
 async function updatePanelUrl(theme) {
   const url = new URL(Constants.kSHORTHAND_URIS.tabbar);
   url.searchParams.set('style', configs.style);
+  url.searchParams.set('reloadMaskImage', !!configs.enableWorkaroundForBug1763420_reloadMaskImage);
   if (!theme)
     theme = await browser.theme.getCurrent();
   browser.sidebarAction.setPanel({ panel: url.href });

webextensions/common/common.js

@@ -313,6 +313,7 @@ export const configs = new Configs({
   enableWorkaroundForBug1409262: false,
   enableWorkaroundForBug1548949: true,
   enableWorkaroundForBug1767165_fixDragEndCoordinates: null, // workaround for https://bugzilla.mozilla.org/show_bug.cgi?id=1767165
+  enableWorkaroundForBug1763420_reloadMaskImage: true, // workaround for https://bugzilla.mozilla.org/show_bug.cgi?id=1763420
   maximumDelayForBug1561879: 500,
   workaroundForBug1548949DroppedTabs: null,
   heartbeatInterval: 1000,

webextensions/sidebar/sidebar.js

@@ -75,6 +75,7 @@ export const onReady   = new EventListenerManager();
 
 let mTargetWindow = null;
 let mInitialized = false;
+let mReloadMaskImage = false; // workaround for https://bugzilla.mozilla.org/show_bug.cgi?id=1763420
 
 let mPromisedTargetWindowResolver;
 const mPromisedTargetWindow = new Promise((resolve, _reject) => {
@@ -98,6 +99,8 @@ document.documentElement.classList.toggle('platform-mac', isMacOS());
   if (isNaN(mTargetWindow) || mTargetWindow < 1)
     mTargetWindow = null;
 
+  mReloadMaskImage = url.searchParams.get('reloadMaskImage') == 'true';
+
   // apply style ASAP!
   const style = url.searchParams.get('style');
   applyTheme({ style });
@@ -336,7 +339,8 @@ async function applyTheme({ style } = {}) {
   ]);
   applyBrowserTheme(theme);
   applyUserStyleRules();
-  reloadAllMaskImages();
+  if (mReloadMaskImage)
+    reloadAllMaskImages();
   Size.update();
 }
 
@@ -921,6 +925,10 @@ async function onConfigChange(changedKey) {
       rootClasses.toggle('simulate-svg-context-fill', configs[changedKey]);
       break;
 
+    case 'enableWorkaroundForBug1763420_reloadMaskImage':
+      mReloadMaskImage = configs[changedKey];
+      break;
+
     default:
       if (changedKey.startsWith('chunkedUserStyleRules'))
         applyUserStyleRules();