From 877cceccfadba8827451d1fe546daca85c9cbf1d Mon Sep 17 00:00:00 2001
From: Jim Mathies <jmathies@mozilla.com>
Date: Tue, 26 Jan 2010 15:40:43 -0600
Subject: [PATCH] Bug 541362 - [OOPP] hang closing tab with Yahoo web messenger
 loaded. r=bent.

--HG--
extra : rebase_source : 007df4403cc58cb02579723991827795e031f6bd
---
 dom/plugins/PluginInstanceChild.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/dom/plugins/PluginInstanceChild.cpp b/dom/plugins/PluginInstanceChild.cpp
index 72c24a961d9..36408235799 100644
--- a/dom/plugins/PluginInstanceChild.cpp
+++ b/dom/plugins/PluginInstanceChild.cpp
@@ -688,6 +688,14 @@ PluginInstanceChild::PluginWindowProc(HWND hWnd,
     if (message == WM_MOUSEACTIVATE)
         self->CallPluginGotFocus();
 
+    // Prevent lockups due to plugins making rpc calls when the parent
+    // is making a synchronous SetFocus api call. (bug 541362) Add more
+    // windowing events as needed for other api.
+    if (message == WM_KILLFOCUS && 
+        ((InSendMessageEx(NULL) & (ISMEX_REPLIED|ISMEX_SEND)) == ISMEX_SEND)) {
+        ReplyMessage(0); // Unblock the caller
+    }
+
     LRESULT res = CallWindowProc(self->mPluginWndProc, hWnd, message, wParam,
                                  lParam);