--- a/configure.in	Mon Aug 13 10:42:45 2007 +0200
+++ b/configure.in	Mon Aug 13 10:43:28 2007 +0200
@@ -2677,6 +2677,7 @@
   AC_CHECKING(for graphics libraries)
 
   dnl Autodetect Xpm
+  xpm_problem=""
   if test -z "$with_xpm"; then
     AC_MSG_CHECKING(for Xpm - no older than 3.4f)
     xe_check_libs=-lXpm
@@ -2686,22 +2687,22 @@
       XpmIncludeVersion != XpmLibraryVersion() ? 1 :
       XpmIncludeVersion < 30406 ? 2 : 0 ;}],
     [./conftest dummy_arg; xpm_status=$?;
-      if test "$?" = "0"; then
+      if test "$xpm_status" = "0"; then
         with_xpm=yes;
       else
         with_xpm=no;
-        if test "$?" = "1"; then
+        if test "$xpm_status" = "1"; then
           xpm_problem="Xpm library version and header file version don't match!"
-        elif test "$?" = "2"; then
+        elif test "$xpm_status" = "2"; then
           xpm_problem="Xpm library version is too old!"
         else
           xpm_problem="Internal xpm detection logic error!"
         fi
         echo "
-*** WARNING *** $problem
+*** WARNING *** $xpm_problem
   I'm not touching that with a 10-foot pole!
   If you really want to use the installed version of Xpm, rerun
-  configure --with-xpm=yes, but don't blame me if XEmacs crashes!"
+  configure and add '--with-xpm=yes', but don't blame me if XEmacs crashes!"
     fi],
     [with_xpm=no])
     xe_check_libs=
@@ -2749,18 +2750,38 @@
   fi
 
   dnl autodetect PNG
+  png_problem=""
+  test -z "$with_png" && { AC_CHECK_FUNC(pow,                  ,with_png=no) }
+  test -z "$with_png" && { AC_CHECK_HEADER(png.h,              ,with_png=no) }
+  test -z "$with_png" && { AC_CHECK_LIB(png, png_read_image,[:],with_png=no) }
   if test -z "$with_png"; then
-    AC_MSG_CHECKING(for png.h - no older than 1.02)
-    AC_EGREP_CPP(yes,
-[#include <png.h>
-#if PNG_LIBPNG_VER >= 10002
-yes
-#endif
-], [AC_MSG_RESULT(yes)], [AC_MSG_RESULT(no); with_png=no])
+    AC_MSG_CHECKING(for workable png version information)
+    xe_check_libs="-lpng -lz"
+    AC_TRY_RUN([#include <png.h>
+    int main(int c, char **v) {
+    if (c == 1) return 0;
+    if (strcmp(png_libpng_ver, PNG_LIBPNG_VER_STRING) != 0) return 1;
+    return (PNG_LIBPNG_VER < 10002) ? 2 : 0 ;}],
+    [./conftest dummy_arg; png_status=$?;
+      if test "$png_status" = "0"; then
+	with_png=yes;
+      else
+	with_png=no;
+	if test "$png_status" = "1"; then
+	  png_problem="PNG library version and header file don't match!"
+        elif test "$png_status" = "2"; then
+	  png_problem="PNG library version too old (pre 1.0.2)!"
+	fi
+	echo "
+*** WARNING *** $png_problem
+  I'm not touching that with a 10-foot pole!
+  If you really want to use the installed version of libPNG, rerun
+  configure and add '--with-png=yes', but don't blame me if XEmacs crashes!"
+    fi],
+    [with_png=no])
+    xe_check_libs=
+    AC_MSG_RESULT($with_png)
   fi
-  test -z "$with_png" && { AC_CHECK_FUNC(pow,                  ,with_png=no) }
-  test -z "$with_png" && { AC_CHECK_LIB(png, png_read_image,[:],with_png=no) }
-  test -z "$with_png" && with_png=yes
   if test "$with_png" = "yes"; then
     AC_DEFINE(HAVE_PNG)
     XE_PREPEND(-lpng, libs_x)
@@ -3924,25 +3945,31 @@
 elif test "$with_x11" = yes; then
   echo "  --------------------------------------------------------------------"
   echo "  WARNING: Compiling without XPM support."
+  if test "$xpm_problem" != ""; then
+    echo "  Reason: $xpm_problem"
+  fi
   echo "  WARNING: You should strongly consider installing XPM."
   echo "  WARNING: Otherwise toolbars and other graphics will look suboptimal."
-  echo "  WARNING: (a copy may be found at ftp://ftp.xemacs.org/pub/xemacs/aux)"
+  echo "  WARNING: (a copy may be found in ftp://ftp.xemacs.org/pub/xemacs/aux)"
   echo "  --------------------------------------------------------------------"
 fi
 if test "$with_png" = yes; then
   echo "  Compiling in support for PNG image handling."
-else
+elif test "$window_system" != "none"; then
   echo "  --------------------------------------------------------------------"
   echo "  WARNING: Compiling without PNG image support."
+  if test "$png_problem" != ""; then
+    echo "  Reason: $png_problem"
+  fi
   echo "  WARNING: You should strongly consider installing the PNG libraries."
   echo "  WARNING: Otherwise certain images and glyphs may not display."
-  echo "  WARNING: (a copy may be found at ftp://ftp.xemacs.org/pub/xemacs/aux)"
+  echo "  WARNING: (a copy may be found in ftp://ftp.xemacs.org/pub/xemacs/aux)"
   echo "  --------------------------------------------------------------------"
 fi
-test "$with_xface" = yes && echo "  Compiling in support for X-Face message headers."
 test "$with_gif"   = yes && echo "  Compiling in support for (builtin) GIF image handling."
 test "$with_jpeg"  = yes && echo "  Compiling in support for JPEG image handling."
 test "$with_tiff"  = yes && echo "  Compiling in support for TIFF image handling."
+test "$with_xface" = yes && echo "  Compiling in support for X-Face message headers."
 case "$with_sound" in
   nas    ) echo "  Compiling in network sound (NAS) support." ;;
   native ) echo "  Compiling in native sound support." ;;