Make the options dialog modal

mail/base/content/mailCore.js

@@ -119,13 +119,13 @@ function openOptionsDialog(containerID, paneURL, itemID)
   const kWindowMediatorContractID = "@mozilla.org/appshell/window-mediator;1";
   const kWindowMediatorIID = Components.interfaces.nsIWindowMediator;
   const kWindowMediator = Components.classes[kWindowMediatorContractID].getService(kWindowMediatorIID);
-  var lastPrefWindow = kWindowMediator.getMostRecentWindow("mozilla:preferences");
+  var lastPrefWindow = kWindowMediator.getMostRecentWindow("Mail:Options");
   
   if (lastPrefWindow)
     lastPrefWindow.focus();
   else 
     openDialog("chrome://communicator/content/pref/pref.xul","PrefWindow", 
-               "chrome,titlebar,resizable=yes", paneURL, containerID, itemID);
+               "chrome,titlebar,resizable,modal", paneURL, containerID, itemID);
 }
 
 function SetBusyCursor(window, enable)

mail/components/prefwindow/content/pref.xul

@@ -10,6 +10,7 @@
         title="&prefWindow.title;" 
         style="&prefWindow.size;"
         onload="Startup();"
+        windowtype="Mail:Options"
         ondialogaccept="return hPrefWindow.onOK(event);"
         ondialogcancel="return hPrefWindow.onCancel(event);"
         persist="width height screenX screenY">