Bug 585785 - Skip the tab closing animation if the tab has the minimal width due to the opening animation not having moved yet. r=gavin a=b

browser/base/content/tabbrowser.xml

@@ -1366,19 +1366,12 @@
             if (!this._beginRemoveTab(aTab, false, null, true))
               return;
 
-            /* Don't animate if:
-                - the caller didn't opt in
-                - this is the last tab in the window
-                - this is a pinned tab
-                - a bunch of other tabs are already closing (arbitrary threshold)
-                - the fadein attribute hasn't been set yet
-                - browser.tabs.animate is false   */
-
-            if (!animate ||
+            if (!animate /* the caller didn't opt in */ ||
                 isLastTab ||
                 aTab.pinned ||
-                this._removingTabs.length > 3 ||
-                aTab.getAttribute("fadein") != "true" ||
+                this._removingTabs.length > 3 /* don't want lots of concurrent animations */ ||
+                aTab.getAttribute("fadein") != "true" /* fade-in transition hasn't been triggered yet */ ||
+                window.getComputedStyle(aTab).maxWidth == "1px" /* fade-in transition hasn't moved yet */ ||
                 !Services.prefs.getBoolPref("browser.tabs.animate")) {
               this._endRemoveTab(aTab);
               return;

browser/base/content/test/Makefile.in

@@ -151,6 +151,7 @@ _BROWSER_FILES = \
                  browser_bug581242.js \
                  browser_bug581253.js \
                  browser_bug581947.js \
+                 browser_bug585785.js \
                  browser_bug585830.js \
                  browser_bug592338.js \
                  browser_bug594131.js \

browser/base/content/test/browser_bug585785.js

@@ -0,0 +1,9 @@
+function test() {
+  waitForExplicitFinish();
+  var tab = gBrowser.addTab();
+  executeSoon(function () {
+    gBrowser.removeTab(tab, {animate:true});
+    ok(!tab.parentNode, "tab successfully removed");
+    finish();
+  });
+}