[gtk-doc] build: allow building without gnome-doc-utils, Fixes #577059

[Stefan Kost <stefkost src gnome org>]

commit 4335ba988d0258e775f7df657ab3d139d5a97c02
Author: Nicola Fontana <ntd entidi it>
Date:   Sat Jun 27 23:09:03 2009 +0300

    build: allow building without gnome-doc-utils, Fixes #577059

 autogen.sh              |    4 +---
 configure.in            |    7 ++++++-
 help/manual/Makefile.am |    7 +++++++
 m4/gnome-doc-utils.m4   |    3 ++-
 4 files changed, 16 insertions(+), 5 deletions(-)
---
diff --git a/autogen.sh b/autogen.sh
index a8771a8..532324c 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -4,7 +4,6 @@
 PROJECT=gtk-doc
 TEST_TYPE=-f
 FILE=gtk-doc.dsl.in
-CONFIGURE_FLAGS=
 
 # a silly hack that generates autoregen.sh but it's handy
 echo "#!/bin/sh" > autoregen.sh
@@ -69,7 +68,6 @@ if gnome-doc-prepare --version < /dev/null > /dev/null 2>&1; then
   echo "* Running gnome-doc-prepare"
   gnome-doc-prepare --copy --force --automake
 else
-  CONFIGURE_FLAGS="$CONFIGURE_FLAGS --disable-scrollkeeper"
   touch gnome-doc-utils.make
 fi
 
@@ -92,7 +90,7 @@ $AUTOMAKE --add-missing -Wno-portability $am_opt || exit $?
 
 cd "$THEDIR"
 
-$srcdir/configure --enable-maintainer-mode "$@" $CONFIGURE_FLAGS || exit $?
+$srcdir/configure --enable-maintainer-mode "$@" || exit $?
 
 echo
 echo "Now type 'make install' to install $PROJECT."
diff --git a/configure.in b/configure.in
index dcd073e..002e326 100644
--- a/configure.in
+++ b/configure.in
@@ -14,7 +14,9 @@ AC_CONFIG_SRCDIR([gtkdoc-common.pl.in])
 AM_INIT_AUTOMAKE([check-news std-options])
 AM_MAINTAINER_MODE
 
-GNOME_DOC_INIT
+dnl Forcing a non-null ACTION-IF-NOT-FOUND disables scrollkeeper if
+dnl gnome-doc-utils is not found but does not invalidate the build.
+GNOME_DOC_INIT([],[],enable_scrollkeeper=no)
 
 # make sure $ACLOCAL_FLAGS are used during a rebuild.
 AC_SUBST([ACLOCAL_AMFLAGS], ["\${ACLOCAL_FLAGS}"])
@@ -227,6 +229,9 @@ test -n "$JADE" \
 test -n "$FOP" \
     && AC_MSG_NOTICE([** XML PDF support enabled, using $FOP]) \
     || AC_MSG_NOTICE([   XML PDF support disabled, no fop available])
+test "x$gdu_cv_have_gdu" = "xyes" \
+    && AC_MSG_NOTICE([** Gnome-doc-utils support enabled]) \
+    || AC_MSG_NOTICE([   Gnome-doc-utils support disabled])
 test "x$enable_scrollkeeper" = "xyes" \
     && AC_MSG_NOTICE([** Scrollkeeper support enabled]) \
     || AC_MSG_NOTICE([   Scrollkeeper support disabled])
diff --git a/help/manual/Makefile.am b/help/manual/Makefile.am
index 82ce76a..b601490 100644
--- a/help/manual/Makefile.am
+++ b/help/manual/Makefile.am
@@ -1,5 +1,12 @@
+if HAVE_GNOME_DOC_UTILS
 include $(top_srcdir)/gnome-doc-utils.make
 dist-hook: doc-dist-hook
+else
+dist-hook:
+	@echo "*** gnome-doc-utils must be installed and enabled in order to make dist"
+	@false
+endif
+
 DOC_MODULE = gtk-doc-manual
 DOC_ENTITIES = fdl-appendix.xml
 DOC_INCLUDES =
diff --git a/m4/gnome-doc-utils.m4 b/m4/gnome-doc-utils.m4
index 04f79bb..4aef712 100644
--- a/m4/gnome-doc-utils.m4
+++ b/m4/gnome-doc-utils.m4
@@ -36,7 +36,8 @@ AM_CONDITIONAL([HAVE_GNOME_DOC_UTILS],[test "$gdu_cv_have_gdu" = "yes"])
 # GNOME_DOC_INIT ([MINIMUM-VERSION],[ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND])
 #
 AC_DEFUN([GNOME_DOC_INIT],
-[
+[AC_REQUIRE([AC_PROG_LN_S])dnl
+
 ifelse([$1],,[gdu_cv_version_required=0.3.2],[gdu_cv_version_required=$1])
 
 PKG_CHECK_EXISTS([gnome-doc-utils >= $gdu_cv_version_required],