bug#19994: 25.0.50; Unicode keyboard input on Windows

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 01 Aug 2015 10:40:05 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 19994@debbugs.gnu.org
> 
> Here's one problem evidently caused by the new code: invoke "emacs -Q"
> and type "M-x" after it starts => you will see "x" being inserted into
> *scratch*.  This doesn't happen if w32-use-fallback-wm-chars-method is
> non-nil.
> 
> This is a one-time problem: all the subsequent "M-x" are handled
> correctly.  It sounds like some initialization somewhere is missing?

I've found that the simple change below fixes this problem.  I
committed it; if you feel it's not the right fix, please propose an
alternative.

Thanks.

commit 0afb8fab99951262e81d6095302de4c84d7e8847
Author: Eli Zaretskii <eliz@gnu.org>
Date:   Sun Aug 2 17:40:19 2015 +0300

    Fix handling of 1st keystroke on MS-Windows
    
    * src/w32fns.c (globals_of_w32fns): Initialize after_deadkey to -1.
    This is needed to correctly handle the session's first keystroke,
    if it has any modifiers.  (Bug#19994)

diff --git a/src/w32fns.c b/src/w32fns.c
index 1c72974..31d23c4 100644
--- a/src/w32fns.c
+++ b/src/w32fns.c
@@ -9442,6 +9442,8 @@ typedef USHORT (WINAPI * CaptureStackBackTrace_proc) (ULONG, ULONG, PVOID *,
   else
     w32_unicode_gui = 0;
 
+  after_deadkey = -1;
+
   /* MessageBox does not work without this when linked to comctl32.dll 6.0.  */
   InitCommonControls ();