[gtk-doc] gtkdocize: Use autoconf --trace for AC_CONFIG_MACRO_DIR

[Stefan Kost <stefkost src gnome org>]

commit 507662aa052a205bc30b179fabf73ac366297db4
Author: David King <amigadave amigadave com>
Date:   Thu Sep 5 21:20:55 2013 +0100

    gtkdocize: Use autoconf --trace for AC_CONFIG_MACRO_DIR
    
    https://bugzilla.gnome.org/show_bug.cgi?id=707424

 gtkdocize.in |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gtkdocize.in b/gtkdocize.in
index 06b67a5..f0399de 100644
--- a/gtkdocize.in
+++ b/gtkdocize.in
@@ -146,7 +146,7 @@ fi
 # matches the the automake fragment.
 # If AC_CONFIG_MACRO_DIR is not used, the macro won't be copied, and
 # the correct flags must be passed to aclocal for it to find the macro.
-m4dir="$srcdir/`cat "$configure" | grep '^AC_CONFIG_MACRO_DIR' | sed -n -e 
's/AC_CONFIG_MACRO_DIR(\([^()]*\))/\1/p' | sed -e 's/^\[\(.*\)\]$/\1/' | sed -e 1q`"
+m4dir="$srcdir"/`autoconf 2>/dev/null --trace 'AC_CONFIG_MACRO_DIR:$1' "$configure"`
 if test -n "$m4dir"; then
   rm -f $m4dir/gtk-doc.m4
   if test "$copy" = yes; then