bug#19428: 25.0.50; X frame size inconsistent at start-up

[martin rudalics]

> Martin's patch caused GCC to complain if --enable-gcc-warnings is used; I 
installed the attached minor further change.

Thanks.  In the past I always built with warnings enabled but had to
disable them a couple of weeks ago: Some code had been injected which
caused making stop here because of warnings treated as errors and I had
no idea how to ignore them and continue compiling.

BTW I'm strongly in favour ...

  ... to change the defaults for Emacs's build procedure
  to generate less output, to help builders and developers focus more
  easily on the diagnostics and warnings that are worth paying attention
  to.

as in the report for bug#19501.  Warnings are typical for such behavior
because they (1) generate too much output and (2) can stop compiling in
a pretty obscure way.

martin