File libicns-libpng.patch of Package icns-utils

--- configure.ac.orig	2015-03-11 12:58:14.083319313 +0100
+++ configure.ac	2015-03-11 12:59:20.168158816 +0100
@@ -152,11 +152,23 @@
     AC_CHECK_LIB(png12, png_create_read_struct, [
     AC_SUBST(PNG_LIBS, "-lpng12")
     ], [
-      AC_MSG_ERROR([cannot find required library png])
+      AC_CHECK_LIB(png14, png_create_read_struct, [
+      AC_SUBST(PNG_LIBS, "-lpng14")
+      ], [
+        AC_CHECK_LIB(png15, png_create_read_struct, [
+        AC_SUBST(PNG_LIBS, "-lpng15")
+        ], [
+          AC_CHECK_LIB(png16, png_create_read_struct, [
+          AC_SUBST(PNG_LIBS, "-lpng16")
+          ], [
+          AC_MSG_ERROR([cannot find required library png])
+          ], [])
+        ], [])
+      ], [])
     ], [])
   ], [])
 ], [])
-AC_CHECK_HEADERS([png.h libpng/png.h libpng10/png.h libpng12/png.h])
+AC_CHECK_HEADERS([png.h libpng/png.h libpng10/png.h libpng12/png.h libpng14/png.h libpng15/png.h libpng16/png.h])
 
 # Check for libopenjpeg, fall back to libjasper if not available
 AC_CHECK_LIB(jasper, jas_init, [