Missing WM_CAPTURECHANGED message

[Christopher Thielen]

Hi wine-devel,

My investigation of https://bugs.winehq.org/show_bug.cgi?id=13683 has 
determined a missing WM_CAPTURECHANGED message is to blame.

At some point in early execution, a WM_CAPTURECHANGED message is sent by 
Windows (but not Wine) which apparently sets off a course of calls that 
prevents this bug.

I wrote some simple WM_CAPTURECHANGED tests but I have not found any 
meaningful differences in execution between Windows and Wine. Put 
another way, I've been unable to trigger u9.exe's specific behavior.

Does anyone have recommendations for debugging Win32 messaging, 
specifically in the case of messages "missing" in Wine? Since I can see 
the missing message being sent by Windows with Spy++, presumably I can 
look back through API calls made before that point and try to replicate 
a test case, but that debugging method sounds fairly lengthy. Is there a 
good tool to capture and replicate all Win32 API calls perhaps?

Any advice would be appreciated, thanks!

- Christopher Thielen