Store the original state of the "Tabs on Top" for user's expectation correctly

defaults/preferences/treestyletab.js

@@ -585,7 +585,6 @@ pref("browser.link.open_newwindow.restriction.override", 0);
 pref("browser.tabs.loadFolderAndReplace.override", false);
 pref("browser.tabs.insertRelatedAfterCurrent.override", false);
 pref("browser.tabs.insertRelatedAfterCurrent.override.force", true);
-pref("extensions.treestyletab.tabsOnTopShouldBeRestored", false);
 
 /**
  * Extra commands for selected tabs (Multiple Tab Handler)

modules/browser.js

@@ -1498,15 +1498,22 @@ TreeStyleTabBrowser.prototype = {
 				// remove ordinal for "tabs on top" https://bugzilla.mozilla.org/show_bug.cgi?id=544815
 				if (this.position == 'top') {
 					this.removeTabStripAttribute('ordinal');
-					// Workaround for https://bugzilla.mozilla.org/show_bug.cgi?id=555987
-					// This should be done when the value of the "ordinal" attribute
-					// is modified dynamically. So, we don' have to do it before
-					// the browser window is completely initialized.
 					if (TabsOnTop && !this.windowService.isPopupWindow &&
 						this.windowService.initialized) {
-						TabsOnTop.enabled = !TabsOnTop.enabled;
+						let currentState = TabsOnTop.enabled;
+						let originalState = this.getTreePref('tabsOnTop.originalState');
+						if (originalState !== null &&
+							currentState != originalState &&
+							this.windowService.tabsOnTopChangingByUI &&
+							!this.windowService.changingTabsOnTop)
+							this.setTreePref('tabsOnTop.originalState', currentState);
+						// Workaround for https://bugzilla.mozilla.org/show_bug.cgi?id=555987
+						// This should be done when the value of the "ordinal" attribute
+						// is modified dynamically. So, we don' have to do it before
+						// the browser window is completely initialized.
+						TabsOnTop.enabled = !currentState;
 						this.Deferred.next(function() {
-							TabsOnTop.enabled = !TabsOnTop.enabled;
+							TabsOnTop.enabled = currentState;
 						}).error(this.defaultDeferredErrorHandler);
 					}
 				}
@@ -1525,10 +1532,7 @@ TreeStyleTabBrowser.prototype = {
 
 		if (TabsOnTop && !this.windowService.isPopupWindow) {
 			let updateTabsOnTop = function() {
-					let tabsWasOnTop = TabsOnTop.enabled;
+					self.windowService.updateTabsOnTop();
-					TabsOnTop.enabled = TabsOnTop.enabled && self.position == 'top' && self.fixed;
-					if (tabsWasOnTop && !TabsOnTop.enabled)
-						self.setTreePref('tabsOnTopShouldBeRestored', true);
 				};
 			// TabsOnTop.enabled is always "false" before the browser window is
 			// completely initialized. So, we have to check it with delay only
@@ -4467,24 +4471,27 @@ TreeStyleTabBrowser.prototype = {
 	onTabsOnTopSyncCommand : function TSTBrowser_onTabsOnTopSyncCommand(aEnabled) 
 	{
 		if (
+			this.windowService.tabsOnTopChangingByUI ||
 			!aEnabled ||
 			this.position != 'top' ||
 			this.fixed ||
-			!this.windowService.isPopupWindow
+			this.windowService.isPopupWindow
 			)
 			return;
+		this.windowService.tabsOnTopChangingByUI = true;
 		var self = this;
 		this.Deferred
 			.next(function() {
 				self.windowService.toggleFixed(self.mTabBrowser);
 			})
 			.next(function() {
-				if (self.window.TabsOnTop.enabled != aEnabled) {
+				if (self.window.TabsOnTop.enabled != aEnabled)
-dump('onTabsOnTopSyncCommand, set to '+aEnabled+'\n');
 					self.window.TabsOnTop.enabled = aEnabled;
-				}
 			})
-			.error(this.defaultDeferredErrorHandler);
+			.error(this.defaultDeferredErrorHandler)
+			.next(function() {
+				self.windowService.tabsOnTopChangingByUI = false;
+			});
 	},
  
 	onTreeStyleTabPrintPreviewEntered : function TSTBrowser_onTreeStyleTabPrintPreviewEntered(aEvent) 

modules/window.js

@@ -387,8 +387,8 @@ TreeStyleTabWindow.prototype = {
 		namespace = void(0);
 		var self = this;
 		var restorePrefs = function() {
-				if (prefs.getPref('extensions.treestyletab.tabsOnTopShouldBeRestored')) {
+				if (prefs.getPref('extensions.treestyletab.tabsOnTop.originalState')) {
-					prefs.clearPref('extensions.treestyletab.tabsOnTopShouldBeRestored');
+					prefs.clearPref('extensions.treestyletab.tabsOnTop.originalState');
 					try {
 						self.browser.treeStyleTab.position = 'top';
 					}
@@ -980,25 +980,40 @@ TreeStyleTabWindow.prototype = {
 	updateTabsOnTop : function TSTWindow_updateTabsOnTop() 
 	{
 		var w = this.window;
-		if (this.isPopupWindow || !('TabsOnTop' in w) || !('enabled' in w.TabsOnTop))
+		if (
+			this.isPopupWindow ||
+			this.tabsOnTopChangingByUI ||
+			this.tabsOnTopChangingByTST ||
+			!('TabsOnTop' in w) ||
+			!('enabled' in w.TabsOnTop)
+			)
 			return;
 
-		var TabsOnTop = w.TabsOnTop;
+		this.tabsOnTopChangingByTST = true;
-		if (!('_tabsOnTopDefaultState' in this))
-			this._tabsOnTopDefaultState = TabsOnTop.enabled;
 
-		if (this.browser.treeStyleTab.position != 'top' ||
+		try {
-			!this.browser.treeStyleTab.fixed) {
+			var TabsOnTop = w.TabsOnTop;
-			if (TabsOnTop.enabled) {
+			var originalState = this.getTreePref('tabsOnTop.originalState');
-				TabsOnTop.enabled = false;
+			if (originalState === null) {
-				this.setTreePref('tabsOnTopShouldBeRestored', true);
+				let current = this.getDefaultPref('browser.tabs.onTop') === null ?
+								TabsOnTop.enabled :
+								this.getPref('browser.tabs.onTop') ;
+				this.setTreePref('tabsOnTop.originalState', originalState = current);
+			}
+
+			if (this.browser.treeStyleTab.position != 'top' ||
+				!this.browser.treeStyleTab.fixed) {
+				if (TabsOnTop.enabled)
+					TabsOnTop.enabled = false;
+			}
+			else {
+				if (TabsOnTop.enabled != originalState)
+					TabsOnTop.enabled = originalState;
+				this.clearTreePref('tabsOnTop.originalState');
 			}
 		}
-		else if ('_tabsOnTopDefaultState' in this) {
+		finally {
-			if (TabsOnTop.enabled!= this._tabsOnTopDefaultState)
+			this.tabsOnTopChangingByTST = false;
-				TabsOnTop.enabled = this._tabsOnTopDefaultState;
-			delete this._tabsOnTopDefaultState;
-			this.setTreePref('tabsOnTopShouldBeRestored', false);
 		}
 	},