--- a/mail/base/content/mailWindowOverlay.xul
+++ b/mail/base/content/mailWindowOverlay.xul
@@ -1966,19 +1966,19 @@
            class="inline-toolbar chromeclass-toolbar"
            toolbarname="&showMessengerToolbarCmd.label;"
            accesskey="&showMessengerToolbarCmd.accesskey;"
            fullscreentoolbar="true" mode="full"
            customizable="true"
            context="toolbar-context-menu"
 #ifdef XP_MACOSX
            iconsize="small"
-           defaultset="button-getmsg,button-newmsg,button-address,spacer,button-tag,spring,gloda-search">
+           defaultset="button-getmsg,button-newmsg,button-address,spacer,button-tag,qfb-show-filter-bar,spring,gloda-search">
 #else
-           defaultset="button-getmsg,button-newmsg,button-address,separator,button-tag,spring,gloda-search">
+           defaultset="button-getmsg,button-newmsg,button-address,separator,button-tag,qfb-show-filter-bar,spring,gloda-search">
 #endif
   </toolbar>
 
   <toolbarset id="customToolbars" context="toolbar-context-menu"/>
 </toolbox>
 
 <!-- The msgNotificationBar appears on top of the message and displays
      information like: junk, contains remote images, or is a suspected phishing

--- a/mail/base/content/messenger.xul
+++ b/mail/base/content/messenger.xul
@@ -321,17 +321,17 @@
            #tabbar-toolbar below. -->
       <hbox id="tabmail-buttons"/>
 
       <toolbar id="tabbar-toolbar" toolboxid="mail-toolbox"
                context="toolbar-context-menu"
                customizable="true"
                mode="icons" defaultmode="icons" lockmode="true"
                iconsize="small" defaulticonsize="small" lockiconsize="true"
-               defaultset="qfb-show-filter-bar"/>
+               defaultset=""/>
 
       <toolbarbutton class="tabs-alltabs-button"
                      id="alltabs-button"
                      type="menu"
                      tooltiptext="&listAllTabs.label;">
         <menupopup class="tabs-alltabs-popup"
                    id="alltabs-popup" position="after_end"
                    tabcontainer="tabcontainer"/>

--- a/mail/base/modules/mailMigrator.js
+++ b/mail/base/modules/mailMigrator.js
@@ -128,17 +128,17 @@ var MailMigrator = {
 
   /**
    * Determine if the UI has been upgraded in a way that requires us to reset
    * some user configuration.  If so, performs the resets.
    */
   _migrateUI: function MailMigrator__migrateUI() {
     // The code for this was ported from
     // mozilla/browser/components/nsBrowserGlue.js
-    const UI_VERSION = 2;
+    const UI_VERSION = 3;
     const MESSENGER_DOCURL = "chrome://messenger/content/messenger.xul#";
     const UI_VERSION_PREF = "mail.ui-rdf.version";
     let currentUIVersion = 0;
 
     try {
       currentUIVersion = Services.prefs.getIntPref(UI_VERSION_PREF);
     } catch(ex) {}
 
@@ -155,18 +155,18 @@ var MailMigrator = {
       // However, the inital implementation of migrateUI swallowed up
       // exceptions, and bumped the value of UI_VERSION_PREF regardless.
       // Now, instead, we fail to bump the UI_VERSION_PREF if something goes
       // wrong, and we've moved the folderPaneBox operation into
       // currentUIVersion < 2 just in case the operation failed for some of
       // our users the first time.
       if (currentUIVersion < 2) {
         // We want to remove old settings that collapse the folderPaneBox
-        let fpbResource = this._rdf.GetResource(MESSENGER_DOCURL +
-                                                "folderPaneBox");
+        let fpbResource = this._rdf.GetResource(MESSENGER_DOCURL
+                                                + "folderPaneBox");
         let collapsedResource = this._rdf.GetResource("collapsed");
         let collapsed = this._getPersist(fpbResource, collapsedResource);
 
         if (collapsed !== null) {
           // We want to override this, and set it to false.  We should really
           // be ignoring this persist attribute, anyhow.
           dirty = true;
           this._unAssert(fpbResource, collapsedResource);
@@ -189,22 +189,62 @@ var MailMigrator = {
               currentSet.indexOf("throbber-box") != -1) {
             dirty = true;
             currentSet = currentSet.replace(/(^|,)throbber-box($|,)/, "$1$2");
             this._setPersist(barResource, currentSetResource, currentSet);
           }
         }
       }
 
+      // In UI version 3, we move the QFB button from the tabbar toolbar to
+      // to the mail toolbar.
+      if (currentUIVersion < 3) {
+        let currentSetResource = this._rdf.GetResource("currentset");
+        let tbtResource = this._rdf.GetResource(MESSENGER_DOCURL
+                                                + "tabbar-toolbar");
+        if (tbtResource !== null) {
+          let currentSet = this._getPersist(tbtResource, currentSetResource);
+          if (currentSet
+              && currentSet.indexOf("qfb-show-filter-bar") != -1) {
+            dirty = true;
+            currentSet = currentSet.replace(/(^|,)qfb-show-filter-bar($|,)/,
+                                            "$1$2");
+            this._setPersist(tbtResource, currentSetResource, currentSet);
+          }
+        }
+
+        let barResource = this._rdf.GetResource(MESSENGER_DOCURL + "mail-bar3");
+        if (barResource !== null) {
+          let currentSet = this._getPersist(barResource, currentSetResource);
+
+          if (currentSet
+              && currentSet.indexOf("qfb-show-filter-bar") == -1) {
+
+            dirty = true;
+            if (currentSet.indexOf("gloda-search") != -1) {
+              // Put the QFB toggle before the gloda-search and any of
+              // spring / spacer / separator.
+              currentSet = currentSet.replace(/(^|,)([spring,|spacer,|separator,]*)gloda-search($|,)/,
+                                              "$1qfb-show-filter-bar,$2gloda-search$3");
+            } else {
+              // If there's no gloda-search, just put the QFB toggle at the end
+              currentSet = currentSet + ",qfb-show-filter-bar";
+            }
+            this._setPersist(barResource, currentSetResource, currentSet);
+          }
+        }
+      }
+
       // Update the migration version.
       Services.prefs.setIntPref(UI_VERSION_PREF, UI_VERSION);
 
     } catch(e) {
       Cu.reportError("Migrating from UI version " + currentUIVersion + " to "
-                     + UI_VERSION + " failed. Will reattempt on next start.");
+                     + UI_VERSION + " failed. Error message was: " + e + " -- "
+                     + "Will reattempt on next start.");
     } finally {
       if (dirty)
         this._dataSource.QueryInterface(Ci.nsIRDFRemoteDataSource).Flush();
       delete this._rdf;
       delete this._dataSource;
     }
   },
 

new file mode 100644
--- /dev/null
+++ b/mail/test/mozmill/migration-to-rdf-ui-3/localstore.rdf
@@ -0,0 +1,48 @@
+<?xml version="1.0"?>
+<RDF:RDF xmlns:NC="http://home.netscape.com/NC-rdf#"
+         xmlns:RDF="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+  <RDF:Description RDF:about="chrome://messenger/content/messenger.xul#attachment-view-toolbar"
+                   iconsize="small" />
+  <RDF:Description RDF:about="chrome://messenger/content/messenger.xul#attachment-view-toolbox"
+                   mode="full"
+                   iconsize="small"
+                   labelalign="end" />
+  <RDF:Description RDF:about="chrome://messenger/content/messenger.xul#header-view-toolbar"
+                   iconsize="small"
+                   currentset="hdrReplyToSenderButton,hdrSmartReplyButton,hdrForwardButton,hdrArchiveButton,hdrJunkButton,hdrTrashButton,abp-toolbarbutton" />
+  <RDF:Description RDF:about="chrome://messenger/content/messenger.xul#header-view-toolbox"
+                   mode="full"
+                   iconsize="small"
+                   labelalign="end" />
+  <RDF:Description RDF:about="chrome://messenger/content/messenger.xul#messengerWindow"
+                   width="1024"
+                   height="1160"
+                   screenX="0"
+                   screenY="0"
+                   sizemode="normal" />
+  <RDF:Description RDF:about="chrome://messenger/content/messenger.xul#mail-toolbar-menubar2"
+                   mode="full"
+                   iconsize="large"
+                   currentset="menubar-items,spring,throbber-box" />
+  <RDF:Description RDF:about="chrome://messenger/content/messenger.xul#tabbar-toolbar"
+                   currentset="qfb-show-filter-bar" />
+  <RDF:Description RDF:about="chrome://messenger/content/messenger.xul#mail-bar3"
+                   currentset="button-getmsg,button-newmsg,button-address,separator,button-tag,spring,separator,spring,spacer,gloda-search" />
+
+  <RDF:Description RDF:about="chrome://messenger/content/messenger.xul">
+    <NC:persist RDF:resource="chrome://messenger/content/messenger.xul#messengerWindow"/>
+    <NC:persist RDF:resource="chrome://messenger/content/messenger.xul#messagepaneboxwrapper"/>
+    <NC:persist RDF:resource="chrome://messenger/content/messenger.xul#header-view-toolbox"/>
+    <NC:persist RDF:resource="chrome://messenger/content/messenger.xul#header-view-toolbar"/>
+    <NC:persist RDF:resource="chrome://messenger/content/messenger.xul#attachment-view-toolbox"/>
+    <NC:persist RDF:resource="chrome://messenger/content/messenger.xul#attachment-view-toolbar"/>
+    <NC:persist RDF:resource="chrome://messenger/content/messenger.xul#abp-hooks"/>
+    <NC:persist RDF:resource="chrome://messenger/content/messenger.xul#folderPaneBox"/>
+    <NC:persist RDF:resource="chrome://messenger/content/messenger.xul#mail-bar3"/>
+  </RDF:Description>
+  <RDF:Description RDF:about="chrome://messenger/content/messenger.xul#folderPaneBox"
+                   width="500"
+                   collapsed="true" />
+  <RDF:Description RDF:about="chrome://messenger/content/messenger.xul#abp-hooks"
+                   currentVersion="2.0.2" />
+</RDF:RDF>

new file mode 100644
--- /dev/null
+++ b/mail/test/mozmill/migration-to-rdf-ui-3/test-migrate-to-rdf-ui-3.js
@@ -0,0 +1,42 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * When moving from ui-rdf 0 to 1, we ensure that we've removed the collapsed
+ * property from the folderPaneBox, but that we still persist width.
+ */
+
+let MODULE_NAME = "test-migrate-to-rdf-ui-3";
+let RELATIVE_ROOT = "../shared-modules";
+let MODULE_REQUIRES = ["folder-display-helpers", "migration-helpers"];
+
+let Cc = Components.classes;
+let Ci = Components.interfaces;
+let Cu = Components.utils;
+
+Cu.import("resource://gre/modules/Services.jsm");
+
+function setupModule(module) {
+  let fdh = collector.getModule("folder-display-helpers");
+  fdh.installInto(module);
+  let mh = collector.getModule("migration-helpers");
+  mh.installInto(module);
+}
+
+/**
+ * Test that the QFB toggle was moved from the tabbar-toolbar to the
+ * mail-bar3.
+ */
+function test_qfb_button_moved() {
+  let currentSet = mc.e("tabbar-toolbar").currentSet;
+  assert_equals(-1, currentSet.indexOf("qfb-show-filter-bar"),
+                "We found the QFB filter toggle where we shouldn't have.");
+
+  // Now make sure that we've got the QFB filter toggle in the mail bar,
+  // and that it is placed before the gloda-search and any spring, spacer,
+  // or separator items.
+  let currentSet = mc.e("mail-bar3").currentSet;
+  assert_not_equals(-1, currentSet.indexOf("button-tag,qfb-show-filter-bar,spring"),
+                "We didn't find the QFB filter toggle where we should have.");
+}

new file mode 100644
--- /dev/null
+++ b/mail/test/mozmill/migration-to-rdf-ui-3/wrapper.py
@@ -0,0 +1,16 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+import shutil
+
+def on_profile_created(profiledir):
+    """
+    On profile creation, this copies localstore.rdf from the current folder to
+    the profile_dir.
+    """
+    # The localstore.rdf file is in the same directory this script is in
+    localstore = os.path.join(os.path.dirname(__file__),
+                              "localstore.rdf")
+    shutil.copy(localstore, profiledir)

--- a/mail/test/mozmill/migration/test-toolbar.js
+++ b/mail/test/mozmill/migration/test-toolbar.js
@@ -41,31 +41,31 @@
 
 var MODULE_NAME = "test-toolbar";
 
 var RELATIVE_ROOT = "../shared-modules";
 var MODULE_REQUIRES = ["folder-display-helpers", "migration-helpers"];
 
 // Use the Windows/Linux settings as the default, but check out setupModule.
 var DEFAULT_TB2_SET = "button-getmsg,button-newmsg,button-address,separator,button-reply,button-replyall,button-replylist,button-forward,separator,button-tag,button-delete,button-junk,button-print,separator,button-goback,button-goforward,spring,gloda-search";
-var DEFAULT_TB3_SET = "button-getmsg,button-newmsg,button-address,separator,button-tag,spring,gloda-search"
+var DEFAULT_TB3_SET = "button-getmsg,button-newmsg,button-address,separator,button-tag,qfb-show-filter-bar,spring,gloda-search"
 var CUSTOM_TB3_SET = "button-getmsg,button-newmsg,button-address,spacer,button-tag,spring,folder-location-container,gloda-search,throbber-box";
 var DEFAULT_TB3_ICONSIZE = "large";
 
 
 function setupModule(module) {
   let fdh = collector.getModule("folder-display-helpers");
   fdh.installInto(module);
   let mh = collector.getModule("migration-helpers");
   mh.installInto(module);
 
   // The Mac has different settings for the toolbar, so adjust for that.
   if (Application.platformIsMac) {
     DEFAULT_TB2_SET = "button-getmsg,button-newmsg,button-address,spacer,button-reply,button-replyall,button-replylist,button-forward,spacer,button-tag,button-delete,button-junk,button-print,spacer,button-goback,button-goforward,spring,gloda-search,throbber-box";
-    DEFAULT_TB3_SET = "button-getmsg,button-newmsg,button-address,spacer,button-tag,spring,gloda-search";
+    DEFAULT_TB3_SET = "button-getmsg,button-newmsg,button-address,spacer,button-tag,qfb-show-filter-bar,spring,gloda-search";
     DEFAULT_TB3_ICONSIZE = "small";
   }
 }
 
 /**
  * Assert that the settings correspond to the default TB2 settings.
  *
  * @param aNewBar the mail-bar3 to check.

--- a/mail/test/mozmill/mozmilltests.list
+++ b/mail/test/mozmill/mozmilltests.list
@@ -11,15 +11,16 @@ folder-tree-modes
 folder-widget
 instrumentation
 junk-commands
 message-header
 message-window
 migration
 migration-from-tb2
 migration-to-rdf-ui-2
+migration-to-rdf-ui-3
 newmailaccount
 notification
 pref-window
 quick-filter-bar
 search-window
 session-store
 tabmail