Change matchbox-keyboard to look for "libpng" instead of "libpng12", and fix the
code so that it works with the 1.2 and 1.5 API.

Upstream-Status: Backport
Signed-off-by: Ross Burton <ross.burton@intel.com>

diff --git a/configure.ac b/configure.ac
index 9678cf7..9bbbd76 100644
--- a/configure.ac
+++ b/configure.ac
@@ -171,24 +171,7 @@ dnl ------ Expat ------------------------------------------------------------
 
 dnl ------ Check for PNG ---------------------------------------------------
 
-AC_MSG_CHECKING(for libpng12)
-
-if $PKG_CONFIG --exists libpng12; then
-        AC_MSG_RESULT(yes)
-        PNG_LIBS=`$PKG_CONFIG --libs libpng12`
-        PNG_CFLAGS=`$PKG_CONFIG --cflags libpng12`
-else
-        AC_MSG_RESULT(no)
-        AC_CHECK_LIB([png], [png_create_read_struct],
-                      [have_png="yes"], [have_png="no"])
-
-        if test x$have_png=xyes && test x$have_png_h=xyes; then
-            PNG_LIBS="-lpng -lz"
-        else
-            AC_MSG_ERROR([*** Cannot find libpng12 ****])
-        fi
-fi
-
+PKG_CHECK_MODULES(PNG, libpng)
 
 dnl ------ Debug Build ------------------------------------------------------
 
diff --git a/src/matchbox-keyboard-image.c b/src/matchbox-keyboard-image.c
index 8accc3e..6b4b0e8 100644
--- a/src/matchbox-keyboard-image.c
+++ b/src/matchbox-keyboard-image.c
@@ -65,7 +65,7 @@ png_file_load (const char *file,
     return NULL;
   }
 
-  if ( setjmp( png_ptr->jmpbuf ) ) {
+  if (setjmp (png_jmpbuf (png_ptr))) {
     png_destroy_read_struct( &png_ptr, &info_ptr, NULL);
     fclose(fd);
     return NULL;