[gimp-gap] added configure.in script pkg-config check message

[Wolfgang Hofer <wolfgangh src gnome org>]

commit 358050effedaae66c7edaf24754a4518a3ae36b1
Author: Wolfgang Hofer <wolfgangh svn gnome org>
Date:   Sat May 5 11:13:30 2012 +0200

    added configure.in script pkg-config check message

 ChangeLog    |    7 +++++++
 configure.in |   11 +++++++----
 2 files changed, 14 insertions(+), 4 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 00dca67..556a7c1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2012-05-05 Wolfgang Hofer <hof gimp org>
+
+- the configure.in script displays error message in case
+  when the pkg-config program is not executable.
+
+ * configure.in
+
 2012-05-02 Wolfgang Hofer <hof gimp org>
 
 - fixed Bug #675188 Frame filename matching misses 8-digit frame numbers
diff --git a/configure.in b/configure.in
index 8b70ac6..0388049 100644
--- a/configure.in
+++ b/configure.in
@@ -1063,13 +1063,16 @@ dnl
 GTHREAD_LIBS=`$PKG_CONFIG --libs gthread-2.0`
 AC_SUBST(GTHREAD_LIBS)
 
-PKGCONFIG=`type pkg-config`
-if test -x "$(PKGCONFIG)" ; then
-  GAP_VLIBS_PNG=`$(PKGCONFIG) --libs libpng`
+pkg_cfg_warning=""
+if test -x "$PKG_CONFIG" ; then
+  dnl pkg_cfg_warning="INFO:pkg-config program is:$PKG_CONFIG"
+  GAP_VLIBS_PNG=`$PKG_CONFIG --libs libpng`
 else
+  pkg_cfg_warning="Error: pkg-config program $PKG_CONFIG could not be executed."
   GAP_VLIBS_PNG="-lpng14"
 fi
 
+
 GAPVIDEOAPI_EXTLIBS="\$(GAP_VLIBS_FFMPEG) \$(GAP_VLIBS_MPEG3) \$(GAP_VLIBS_PNG) -lz \$(GTHREAD_LIBS) \$(GAP_PTHREAD_LIB) -lm"
 GAPVIDEOAPI_EXTINCS="\$(GAP_VINCS_FFMPEG) \$(GAP_VINCS_MPEG3)"
 AC_SUBST(GAPVIDEOAPI_EXTLIBS)
@@ -1215,4 +1218,4 @@ docs/reference/Makefile
 docs/reference/txt/Makefile
 ])
 
-AC_MSG_RESULT($frontends_warning $audio_warning $videoapi_warning $moved_old_ffmpeg_warn $moved_old_libmpeg3_warn $vid_ffmpeg_warning $yasm_warn $vid_mpeg3_warning $vid_quicktime_warning $vid_xvidcore_warning)
+AC_MSG_RESULT($frontends_warning $audio_warning $videoapi_warning $moved_old_ffmpeg_warn $moved_old_libmpeg3_warn $vid_ffmpeg_warning $yasm_warn $vid_mpeg3_warning $vid_quicktime_warning $vid_xvidcore_warning $pkg_cfg_warning)