Subject: 27.0.50; GCC 7 warning due to -Wformat-overflow

From: Ken Brown <[email-masked]>
Date: Fri, 20 Jul 2018 18:02:07 -0400

The Cygwin-w32 build has turned up another GCC 7 warning:

../../master/src/w32term.c: In function ‘x_draw_glyph_string’:
../../master/src/w32term.c:1477:27: warning: ‘__builtin___sprintf_chk’ 
may write a terminating nul past the end of the destination 
[-Wformat-overflow=]
     sprintf ((char *) buf, "%0*X",
                            ^
../../master/src/w32term.c:1477:4: note: ‘__builtin___sprintf_chk’ 
output between 5 and 8 bytes into a destination of size 7
     sprintf ((char *) buf, "%0*X",
     ^
The method that Paul used in bug#32189 could be used here too, but I'm
not sure it's worth the trouble.  My inclination is to just increase the
buffer size from 7 to 8.

Ken