bug#25875: 26.0.50; Hang logging out of MS-Windows

[Eli Zaretskii <eliz@gnu.org>]

> From: Richard Copley <rcopley@gmail.com>
> Date: Sat, 25 Feb 2017 19:35:28 +0000
> 
> On MS Windows, Emacs sometimes hangs when shutting down or logging out.

How did you shut it down in this case?  This part:

> #2  0x0000000400266caf in sys_sleep (seconds=1000)
>     at ../../repo/src/w32.c:3075
> No locals.
> #3  0x0000000400238225 in w32_wnd_proc (hwnd=0x1f076a, msg=22, wParam=1,
>     lParam=0) at ../../repo/src/w32fns.c:4805

seems to indicate that you shut down your Windows session or
something?

> (This build includes 5114b3a204..: Eli Zaretskii 2017-02-23 Avoid
> quitting inside a critical section on MS-Windows, see #25279).
> 
> I've included backtraces for all the threads having Emacs functions on
> the stack, because I can't tell which are deadlocked, if any. (2 and 3?)

I'm not sure I see any of them deadlocked.  Each one is waiting for
something it should.

> Also got these from thread 2, frame 2.
> 
> (gdb) print crit
> $1 = (CRITICAL_SECTION *) 0x401bc6a20 <crit_real>
> (gdb) print crit_real
> $2 = {DebugInfo = 0xffffffffffffffff, LockCount = -1, RecursionCount = 0,
>   OwningThread = 0x0, LockSemaphore = 0x0, SpinCount = 33556432}

Any reasons why this drew your attention?

> Configured using:
>  'configure --prefix=/mingw64 --with-modules
>  --enable-locallisppath=/c/emacs/site-lisp
>  CPPFLAGS=-D_WIN32_WINNT=_WIN32_WINNT_WIN7 'CFLAGS=-O0 -g -ggdb''

Why are you setting _WIN32_WINNT to this value when compiling Emacs?