Bug 1491786 - Access selectedItem only once in _notifyBackgroundTab. r=dao
authorMarkus Staab <markus.staab@redaxo.de>
Thu, 20 Sep 2018 08:39:48 +0000
changeset 437391 90b5ea4678b3
parent 437390 d51a5d2bc3a9
child 437392 ea436a9177b5
push id34681
push userebalazs@mozilla.com
push dateThu, 20 Sep 2018 13:21:10 +0000
treeherdermozilla-central@10664ff20476 [default view] [failures only]
perfherder[talos] [build metrics] [platform microbench] (compared to previous push)
reviewersdao
bugs1491786
milestone64.0a1
first release with
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last release without
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Bug 1491786 - Access selectedItem only once in _notifyBackgroundTab. r=dao Differential Revision: https://phabricator.services.mozilla.com/D6321
browser/base/content/tabbrowser.xml
--- a/browser/base/content/tabbrowser.xml
+++ b/browser/base/content/tabbrowser.xml
@@ -759,18 +759,19 @@
           // DOMRect left/right properties are immutable.
           tab = {left: tab.left, right: tab.right};
 
           // Is the new tab already completely visible?
           if (scrollRect.left <= tab.left && tab.right <= scrollRect.right)
             return;
 
           if (this.arrowScrollbox.smoothScroll) {
-            let selected = !this.selectedItem.pinned &&
-                           this.selectedItem.getBoundingClientRect();
+            let selectedTab = this.selectedItem;
+            let selected = !selectedTab.pinned &&
+                           selectedTab.getBoundingClientRect();
 
             // Can we make both the new tab and the selected tab completely visible?
             if (!selected ||
                 Math.max(tab.right - selected.left, selected.right - tab.left) <=
                   scrollRect.width) {
               this.arrowScrollbox.ensureElementIsVisible(aTab);
               return;
             }