fixed issue 349227: Uninit error due to DuplicateHandle failure - add check on DuplicateHandle and …

content/public/test/mock_render_process_host.cc

Index: content/public/test/mock_render_process_host.cc
diff --git a/content/public/test/mock_render_process_host.cc b/content/public/test/mock_render_process_host.cc
index a2b058ad890d794dcd426dacaaa28b883157d13f..884ad306bc0847097fc93bc879d5fcd423ed6847 100644
--- a/content/public/test/mock_render_process_host.cc
+++ b/content/public/test/mock_render_process_host.cc
@@ -144,8 +144,9 @@ bool MockRenderProcessHost::Send(IPC::Message* msg) {
 TransportDIB* MockRenderProcessHost::MapTransportDIB(TransportDIB::Id dib_id) {
 #if defined(OS_WIN)
   HANDLE duped;

[sky, 2014/03/05 17:36:50]

Can you instead explicitly set to duped to NULL here?

[zhaoqin, 2014/03/05 19:09:42]

I think it is better to set on failure instead of here.
Because the DuplicateHandle may set duped to be any value (e.g.,
INVALID_HANDLE_VALUE) if the call failed and the value may change cross windows
versions, since the behavior is not documented.
Setting duped to be NULL on failure will handle such cases, so it is safer.

-  DuplicateHandle(GetCurrentProcess(), dib_id.handle, GetCurrentProcess(),
-                  &duped, 0, TRUE, DUPLICATE_SAME_ACCESS);
+  if (!DuplicateHandle(GetCurrentProcess(), dib_id.handle, GetCurrentProcess(),
+                       &duped, 0, TRUE, DUPLICATE_SAME_ACCESS))
+    duped = NULL;

[Will Harris, 2014/03/05 17:40:35]

should this be INVALID_HANDLE_VALUE?

[jschuh, 2014/03/05 17:52:03]

No. INVALID_HANDLE_VALUE can bite you because it aliases to the process
pseudo-handle. NULL should be used instead, except for when dealing with the
small number of Win16-derived APIs that require INVALID_HANDLE_VALUE (e.g.
CreateFile and friends).

   return TransportDIB::Map(duped);
 #elif defined(TOOLKIT_GTK)
   return TransportDIB::Map(dib_id.shmkey);