composer is unusable (101142). r/sr=hyatt

xpfe/global/resources/content/bindings/tabbox.xml

@@ -123,6 +123,9 @@
           while (parent && parent.localName != 'tabbox')
             parent = parent.parentNode;
 
+          if (!parent)
+            return val;
+
           var tabpanels = parent.getElementsByTagNameNS(
                                "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul",
                                "tabpanels");
@@ -173,7 +176,7 @@
     <content>
       <xul:hbox class="tab-box" flex="1" align="center">
         <xul:image class="tab-image" inherits="src"/>
-        <xul:text class="tab-text" inherits="value=label,accesskey,crop,disabled"/>
+        <xul:text flex="1" class="tab-text" inherits="value=label,accesskey,crop,disabled"/>
       </xul:hbox>
     </content>