From d488948063f9c996f035c51ca7d4e6a4aea3fdf3 Mon Sep 17 00:00:00 2001
From: Alexandre Poirot <poirot.alex@gmail.com>
Date: Thu, 20 Mar 2014 09:33:18 -0400
Subject: [PATCH] Bug 985555 - Prevent creating multiple markup view iframes
 when browsing in history. r=bgrins

---
 browser/devtools/inspector/inspector-panel.js | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/browser/devtools/inspector/inspector-panel.js b/browser/devtools/inspector/inspector-panel.js
index 9c4fe10a78c..bd0d5000f6b 100644
--- a/browser/devtools/inspector/inspector-panel.js
+++ b/browser/devtools/inspector/inspector-panel.js
@@ -318,7 +318,13 @@ InspectorPanel.prototype = {
     this._destroyMarkup();
     this.isDirty = false;
 
-    this._getDefaultNodeForSelection().then(defaultNode => {
+    let onNodeSelected = defaultNode => {
+      // Cancel this promise resolution as a new one had
+      // been queued up.
+      if (this._pendingSelection != onNodeSelected) {
+        return;
+      }
+      this._pendingSelection = null;
       this.selection.setNodeFront(defaultNode, "navigateaway");
 
       this._initMarkup();
@@ -330,7 +336,9 @@ InspectorPanel.prototype = {
         this.setupSearchBox();
         this.emit("new-root");
       });
-    });
+    };
+    this._pendingSelection = onNodeSelected;
+    this._getDefaultNodeForSelection().then(onNodeSelected);
   },
 
   _selectionCssSelector: null,