From c44fa859dc53c5a3d4442172fd7f7dbc9451ea47 Mon Sep 17 00:00:00 2001
From: YUKI Hiroshi <shimoda@clear-code.com>
Date: Thu, 7 Jul 2016 18:39:42 +0900
Subject: [PATCH] Open new tab next to the current tab correctly, even if the
 current tab is the last tab

---
 modules/base.js    | 25 +++++++++++++++++++------
 modules/browser.js |  6 ++++++
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/modules/base.js b/modules/base.js
index 63d8541f..c6af8e29 100644
--- a/modules/base.js
+++ b/modules/base.js
@@ -1307,11 +1307,14 @@ var TreeStyleTabBase = inherit(TreeStyleTabConstants, {
   
 /* notify "ready to open child tab(s)" */ 
 	
-	readyToOpenChildTab : function TSTBase_readyToOpenChildTab(aTabOrSomething, aMultiple, aInsertBefore) /* PUBLIC API */ 
+	readyToOpenChildTab : function TSTBase_readyToOpenChildTab(aTabOrSomething, aMultiple, aOptions) /* PUBLIC API */ 
 	{
 		if (!utils.getTreePref('autoAttach'))
 			return false;
 
+		if (aOptions instanceof Ci.nsIDOMElement) // for backward compatibility
+			aOptions = { insertBefore : aOptions };
+
 		var browser = this.getBrowserFromTabBrowserElements(aTabOrSomething);
 		if (!browser)
 			return false;
@@ -1325,10 +1328,15 @@ var TreeStyleTabBase = inherit(TreeStyleTabConstants, {
 		ownerBrowser.treeStyleTab.ensureTabInitialized(parentTab);
 		var parentId = parentTab.getAttribute(this.kID);
 
-		var refId = null;
-		if (aInsertBefore) {
+		var insertBefore = null;
+		if (aOptions.insertBefore) {
 			ownerBrowser.treeStyleTab.ensureTabInitialized(parentTab);
-			refId = aInsertBefore.getAttribute(this.kID);
+			insertBefore = aOptions.insertBefore.getAttribute(this.kID);
+		}
+		var insertAfter = null;
+		if (aOptions.insertAfter) {
+			ownerBrowser.treeStyleTab.ensureTabInitialized(parentTab);
+			insertAfter = aOptions.insertAfter.getAttribute(this.kID);
 		}
 
 		logWithStackTrace('new child tab is requested.');
@@ -1337,7 +1345,8 @@ var TreeStyleTabBase = inherit(TreeStyleTabConstants, {
 		ownerBrowser.treeStyleTab.readiedToAttachMultiple = aMultiple || false ;
 		ownerBrowser.treeStyleTab.multipleCount           = aMultiple ? 0 : -1 ;
 		ownerBrowser.treeStyleTab.parentTab               = parentId;
-		ownerBrowser.treeStyleTab.insertBefore            = refId;
+		ownerBrowser.treeStyleTab.insertBefore            = insertBefore;
+		ownerBrowser.treeStyleTab.insertAfter             = insertAfter;
 
 		return true;
 	},
@@ -1411,12 +1420,16 @@ var TreeStyleTabBase = inherit(TreeStyleTabConstants, {
 
 		var parentTab = this.getParentTab(tab);
 		var nextTab = this.getNextSiblingTab(tab) || this.getNextTab(tab);
+		var previousTab = this.getPreviousTab(tab);
 		if (parentTab) {
 			/**
 			 * If the base tab has a parent, open the new tab as a child of
 			 * the parent tab.
 			 */
-			return this.readyToOpenChildTab(parentTab, false, nextTab);
+			return this.readyToOpenChildTab(parentTab, false, {
+				insertBefore : nextTab,
+				insertAfter  : previousTab
+			});
 		}
 		else {
 			/**
diff --git a/modules/browser.js b/modules/browser.js
index 5b99065a..df074b47 100644
--- a/modules/browser.js
+++ b/modules/browser.js
@@ -3244,6 +3244,7 @@ TreeStyleTabBrowser.prototype = inherit(TreeStyleTabWindow.prototype, {
 		  'readiedToAttachNewTab: '+this.readiedToAttachNewTab,
 		  'parentTab: '+this.parentTab + ' (' + this.getTabById(this.parentTab) + ')',
 		  'insertBefore: '+this.insertBefore,
+		  'insertAfter: '+this.insertAfter,
 		  'treeStructure: '+this.treeStructure
 		].join('\n  '));
 
@@ -3287,6 +3288,11 @@ TreeStyleTabBrowser.prototype = inherit(TreeStyleTabWindow.prototype, {
 				newIndex = refTab._tPos;
 				log('  newIndex => '+newIndex+' (from "insertBefore")');
 			}
+			else if (this.insertAfter &&
+				(refTab = this.getTabById(this.insertAfter))) {
+				newIndex = refTab._tPos + 1;
+				log('  newIndex => '+newIndex+' (from "insertAfter")');
+			}
 			else if (
 				parent &&
 				utils.getTreePref('insertNewChildAt') == this.kINSERT_FISRT &&