diff --git a/install-sh b/install-sh
index 6781b98..a5897de 100755
--- a/install-sh
+++ b/install-sh
@@ -1,7 +1,7 @@
 #!/bin/sh
 # install - install a program, script, or datafile
 
-scriptversion=2009-04-28.21; # UTC
+scriptversion=2006-12-25.00
 
 # This originates from X11R5 (mit/util/scripts/install.sh), which was
 # later released in X11R6 (xc/config/util/install.sh) with the
@@ -515,6 +515,5 @@ done
 # eval: (add-hook 'write-file-hooks 'time-stamp)
 # time-stamp-start: "scriptversion="
 # time-stamp-format: "%:y-%02m-%02d.%02H"
-# time-stamp-time-zone: "UTC"
-# time-stamp-end: "; # UTC"
+# time-stamp-end: "$"
 # End:
diff --git a/macros/png-check.m4 b/macros/png-check.m4
index f428ea5..fae7634 100644
--- a/macros/png-check.m4
+++ b/macros/png-check.m4
@@ -6,36 +6,17 @@ dnl Test for the libpng and define PNG_CFLAGS, PNG_LIBS, and HAVE_LIBPNG
 
 AC_DEFUN([LB_CHECK_PNG],
 [
-PNG_LIBS=
-PNG_CFLAGS=
+# This is because the first PKG_CHECK_MODULES call is inside a conditional.
+PKG_PROG_PKG_CONFIG
 
-AC_ARG_WITH(png,[
-   --with-png= <path>|yes Enable use of PNG library.
-],[
-if test "$withval" = yes ; then
-    AC_CHECK_LIB([png], [png_create_write_struct_2], [
-        AC_DEFINE(HAVE_LIBPNG,1,Enable use of libpng)
-    	PNG_LIBS="-lpng"
-    ])
-elif test "$withval" != no ; then
-    BACKUP_LIBS=$LIBS
-    LIBS=$withval/lib
-    AC_CHECK_LIB([png], [png_create_write_struct_2],[
-            AC_DEFINE(HAVE_LIBPNG,1,Enable use of libpng)
-	    PNG_CFLAGS="-I$withval/include -lpng"
-	    PNG_LIBS="-L$withval/lib -lpng"
-    ],[
-	    AC_MSG_WARN([Could not find libpng in path $withval, disabling])
-    ])
-    LIBS=$BACKUP_LIBS
-fi
-],[
-    AC_CHECK_LIB([png], [png_create_write_struct_2], [
-    	AC_DEFINE(HAVE_LIBPNG,1,Enable use of libpng)
-    	PNG_LIBS="-lpng"
-    ],[AC_MSG_RESULT(not found)])
-])
-
-AC_SUBST(PNG_CFLAGS)
-AC_SUBST(PNG_LIBS)
+AC_ARG_WITH([png],
+  [AS_HELP_STRING([--with-png],
+    [support handling png files @<:@default=check@:>@])],
+  [],
+  [with_png=check])
+AS_CASE(["$with_png"],
+  [yes], [PKG_CHECK_MODULES([PNG], [libpng], [HAVE_LIBPNG=1])],
+  [no], [],
+  [PKG_CHECK_MODULES([PNG], [libpng], [HAVE_LIBPNG=1], [HAVE_LIBPNG=0])])
+AM_CONDITIONAL([USE_LIBPNG], [test "$with_png" != no -a "$HAVE_LIBPNG" == "1"])
 ])