Index: m4/pkg.m4
===================================================================
--- m4/pkg.m4	(revision 807385298d5e0a6a503e30ddb46f8b3a5a9b1534)
+++ m4/pkg.m4	(revision 650fb2c030491f5d6668ad439b83a6a6b7b9870e)
@@ -1,3 +1,4 @@
 # pkg.m4 - Macros to locate and utilise pkg-config.            -*- Autoconf -*-
+# serial 1 (pkg-config-0.24)
 # 
 # Copyright © 2004 Scott James Remnant <scott@netsplit.com>.
@@ -26,6 +27,10 @@
 AC_DEFUN([PKG_PROG_PKG_CONFIG],
 [m4_pattern_forbid([^_?PKG_[A-Z_]+$])
-m4_pattern_allow([^PKG_CONFIG(_PATH)?$])
-AC_ARG_VAR([PKG_CONFIG], [path to pkg-config utility])dnl
+m4_pattern_allow([^PKG_CONFIG(_(PATH|LIBDIR|SYSROOT_DIR|ALLOW_SYSTEM_(CFLAGS|LIBS)))?$])
+m4_pattern_allow([^PKG_CONFIG_(DISABLE_UNINSTALLED|TOP_BUILD_DIR|DEBUG_SPEW)$])
+AC_ARG_VAR([PKG_CONFIG], [path to pkg-config utility])
+AC_ARG_VAR([PKG_CONFIG_PATH], [directories to add to pkg-config's search path])
+AC_ARG_VAR([PKG_CONFIG_LIBDIR], [path overriding pkg-config's built-in search path])
+
 if test "x$ac_cv_env_PKG_CONFIG_set" != "xset"; then
 	AC_PATH_TOOL([PKG_CONFIG], [pkg-config])
@@ -40,5 +45,4 @@
 		PKG_CONFIG=""
 	fi
-		
 fi[]dnl
 ])# PKG_PROG_PKG_CONFIG
@@ -49,8 +53,8 @@
 # to PKG_CHECK_MODULES(), but does not set variables or print errors.
 #
-#
-# Similar to PKG_CHECK_MODULES, make sure that the first instance of
-# this or PKG_CHECK_MODULES is called, or make sure to call
-# PKG_CHECK_EXISTS manually
+# Please remember that m4 expands AC_REQUIRE([PKG_PROG_PKG_CONFIG])
+# only at the first occurence in configure.ac, so if the first place
+# it's called might be skipped (such as if it is within an "if", you
+# have to call PKG_CHECK_EXISTS manually
 # --------------------------------------------------------------
 AC_DEFUN([PKG_CHECK_EXISTS],
@@ -58,23 +62,21 @@
 if test -n "$PKG_CONFIG" && \
     AC_RUN_LOG([$PKG_CONFIG --exists --print-errors "$1"]); then
-  m4_ifval([$2], [$2], [:])
+  m4_default([$2], [:])
 m4_ifvaln([$3], [else
   $3])dnl
 fi])
 
-
 # _PKG_CONFIG([VARIABLE], [COMMAND], [MODULES])
 # ---------------------------------------------
 m4_define([_PKG_CONFIG],
-[if test -n "$PKG_CONFIG"; then
-    if test -n "$$1"; then
-        pkg_cv_[]$1="$$1"
-    else
-        PKG_CHECK_EXISTS([$3],
-                         [pkg_cv_[]$1=`$PKG_CONFIG --[]$2 "$3" 2>/dev/null`],
-			 [pkg_failed=yes])
-    fi
-else
-	pkg_failed=untried
+[if test -n "$$1"; then
+    pkg_cv_[]$1="$$1"
+ elif test -n "$PKG_CONFIG"; then
+    PKG_CHECK_EXISTS([$3],
+                     [pkg_cv_[]$1=`$PKG_CONFIG --[]$2 "$3" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes ],
+		     [pkg_failed=yes])
+ else
+    pkg_failed=untried
 fi[]dnl
 ])# _PKG_CONFIG
@@ -118,14 +120,15 @@
 
 if test $pkg_failed = yes; then
+   	AC_MSG_RESULT([no])
         _PKG_SHORT_ERRORS_SUPPORTED
         if test $_pkg_short_errors_supported = yes; then
-	        $1[]_PKG_ERRORS=`$PKG_CONFIG --short-errors --errors-to-stdout --print-errors "$2"`
+	        $1[]_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "$2" 2>&1`
         else 
-	        $1[]_PKG_ERRORS=`$PKG_CONFIG --errors-to-stdout --print-errors "$2"`
+	        $1[]_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "$2" 2>&1`
         fi
 	# Put the nasty error message in config.log where it belongs
 	echo "$$1[]_PKG_ERRORS" >&AS_MESSAGE_LOG_FD
 
-	ifelse([$4], , [AC_MSG_ERROR(dnl
+	m4_default([$4], [AC_MSG_ERROR(
 [Package requirements ($2) were not met:
 
@@ -135,10 +138,9 @@
 installed software in a non-standard prefix.
 
-_PKG_TEXT
-])],
-		[AC_MSG_RESULT([no])
-                $4])
+_PKG_TEXT])[]dnl
+        ])
 elif test $pkg_failed = untried; then
-	ifelse([$4], , [AC_MSG_FAILURE(dnl
+     	AC_MSG_RESULT([no])
+	m4_default([$4], [AC_MSG_FAILURE(
 [The pkg-config script could not be found or is too old.  Make sure it
 is in your PATH or set the PKG_CONFIG environment variable to the full
@@ -147,11 +149,11 @@
 _PKG_TEXT
 
-To get pkg-config, see <http://pkg-config.freedesktop.org/>.])],
-		[$4])
+To get pkg-config, see <http://pkg-config.freedesktop.org/>.])[]dnl
+        ])
 else
 	$1[]_CFLAGS=$pkg_cv_[]$1[]_CFLAGS
 	$1[]_LIBS=$pkg_cv_[]$1[]_LIBS
         AC_MSG_RESULT([yes])
-	ifelse([$3], , :, [$3])
+	$3
 fi[]dnl
 ])# PKG_CHECK_MODULES
