Consult libpng-config more consistently.
commit6f074205d30c6922db52fdf9a63b9e0467fd82c1
authorPaul Eggert <eggert@cs.ucla.edu>
Fri, 2 May 2014 19:34:03 +0000 (2 12:34 -0700)
committerPaul Eggert <eggert@cs.ucla.edu>
Fri, 2 May 2014 19:34:03 +0000 (2 12:34 -0700)
treee739dc5474dbc555ff87c612bc4cc9b274890f1d
parentcb9af965374fd1537b1b82705642c5c03d04c4d2
Consult libpng-config more consistently.

* configure.ac (edit_cflags): Move this up and to the top level,
so that PNG_CFLAGS can use it too.
(PNG_CFLAGS): New var.
(png_longjmp): Use PNG_CFLAGS when checking.
(LIBPNG): Be consistent about -lpng16 etc; e.g., don't use -lpng16
in some places and -lpng in others.  Test libpng-config's exit
status.  If it succeeds, use its output rather than appending -lz -lm.
* src/Makefile.in (PNG_CFLAGS): New var.
(ALL_CFLAGS): Use it.
* src/image.c [HAVE_PNG]: Don't worry about <libpng/png.h>, as
CFLAGS now handles this.

Fixes: debbugs:17339
ChangeLog
configure.ac
src/ChangeLog
src/Makefile.in
src/image.c