Back out Dão's patch from bug 392870 as a possible cause of the Ts regression.

browser/app/profile/firefox.js

@@ -266,10 +266,6 @@ pref("browser.link.open_newwindow", 3);
 pref("browser.link.open_newwindow.restriction", 2);
 
 // Tab browser preferences.
-pref("browser.tabs.autoHide", false);
-pref("browser.tabs.warnOnClose", true);
-pref("browser.tabs.warnOnOpen", true);
-pref("browser.tabs.maxOpenBeforeWarn", 15);
 pref("browser.tabs.loadInBackground", true);
 pref("browser.tabs.loadFolderAndReplace", true);
 pref("browser.tabs.opentabfor.middleclick", true);

browser/base/content/browser.js

@@ -1374,6 +1374,7 @@ AutoHideTabbarPrefListener.prototype =
       catch (e) {
       }
       gBrowser.setStripVisibilityTo(aVisible);
+      gPrefService.setBoolPref("browser.tabs.forceHide", false);
     }
   }
 }
@@ -1746,8 +1747,17 @@ function BrowserCloseTabOrWindow()
   }
 #endif
 
-  // If the current tab is the last one, this will close the window.
-  gBrowser.removeCurrentTab();
+  if (gBrowser.tabContainer.childNodes.length > 1 ||
+      window.toolbar.visible && !gPrefService.getBoolPref("browser.tabs.autoHide")) {
+    // Just close the tab (and focus the address bar if it was the last one).
+    var isLastTab = gBrowser.tabContainer.childNodes.length == 1;
+    gBrowser.removeCurrentTab();
+    if (isLastTab && gURLBar)
+      setTimeout(function() { gURLBar.focus(); }, 0);
+    return;
+  }
+
+  closeWindow(true);
 }
 
 function BrowserTryToCloseWindow()

browser/base/content/tabbrowser.xml

@@ -1166,6 +1166,8 @@
             if (this.mStrip.collapsed)
               this.setStripVisibilityTo(true);
 
+            this.mPrefs.setBoolPref("browser.tabs.forceHide", false);
+
             // wire up a progress listener for the new browser object.
             var position = this.mTabContainer.childNodes.length-1;
             var tabListener = this.mTabProgressListener(t, b, blank);
@@ -1339,22 +1341,18 @@
             if (aTab.localName != "tab")
               aTab = this.mCurrentTab;
 
+            var l = this.mTabContainer.childNodes.length;
+            if (l == 1 && this.mPrefs.getBoolPref("browser.tabs.autoHide")) {
+              // hide the tab bar
+              this.mPrefs.setBoolPref("browser.tabs.forceHide", true);
+              this.setStripVisibilityTo(false);
+              return;
+            }
+
             var ds = this.getBrowserForTab(aTab).docShell;
             if (ds.contentViewer && !ds.contentViewer.permitUnload())
               return;
 
-            var l = this.mTabContainer.childNodes.length;
-            if (l == 1) {
-              closeWindow(true);
-              return;
-            }
-            if (l == 2) {
-              var autohide = this.mPrefs.getBoolPref("browser.tabs.autoHide");
-              var tabStripHide = !window.toolbar.visible;
-              if (autohide || tabStripHide)
-                this.setStripVisibilityTo(false);
-            }
-
             // see notes in addTab
             var _delayedUpdate = function(aTabContainer) {
               aTabContainer.adjustTabstrip();
@@ -1362,6 +1360,19 @@
             }
             setTimeout(_delayedUpdate, 0, this.mTabContainer);
 
+            if (l == 1) {
+              // add a new blank tab to replace the one we're about to close
+              // (this ensures that the remaining tab is as good as new)
+              this.addTab("about:blank");
+              l++;
+            }
+            else if (l == 2) {
+              var autohide = this.mPrefs.getBoolPref("browser.tabs.autoHide");
+              var tabStripHide = !window.toolbar.visible;
+              if (autohide || tabStripHide)
+                this.setStripVisibilityTo(false);
+            }
+
             // We're committed to closing the tab now.  
             // Dispatch a notification.
             // We dispatch it before any teardown so that event listeners can
@@ -1538,8 +1549,9 @@
             if (!this.mAddProgressListenerWasCalled) {
               this.mAddProgressListenerWasCalled = true;
               var autoHide = this.mPrefs.getBoolPref("browser.tabs.autoHide");
+              var forceHide = this.mPrefs.getBoolPref("browser.tabs.forceHide");
               var tabStripHide = !window.toolbar.visible;
-              if (!autoHide && !tabStripHide)
+              if (!autoHide && !forceHide && !tabStripHide)
                 this.setStripVisibilityTo(true);
             }
 

modules/libpref/src/init/all.js

@@ -172,10 +172,29 @@ pref("browser.frames.enabled", true);
 // form submission
 pref("browser.forms.submit.backwards_compatible", true);
 
+// xxxbsmedberg more toolkit prefs?
+// Tab browser preferences.
+pref("browser.tabs.autoHide", true);
+pref("browser.tabs.forceHide", false);
+pref("browser.tabs.warnOnClose", true);
+pref("browser.tabs.warnOnCloseOther", true);
+pref("browser.tabs.warnOnOpen", true);
+pref("browser.tabs.maxOpenBeforeWarn", 15);
+// 0 = append, 1 = replace
+pref("browser.tabs.loadGroup", 1);
+
 pref("toolkit.scrollbox.smoothScroll", true);
 pref("toolkit.scrollbox.scrollIncrement", 20);
 pref("toolkit.scrollbox.clickToScroll.scrollDelay", 150);
 
+// lets new tab/window load something different than first window
+// -1 - use navigator startup preference
+//  0 - loads blank page
+//  1 - loads home page
+//  2 - loads last page visited
+pref("browser.tabs.loadOnNewTab", 0);
+pref("browser.windows.loadOnNewWindow", 1);
+
 // view source
 pref("view_source.syntax_highlight", true);
 pref("view_source.wrap_long_lines", false);