[gdm] build: Add --disable-documentation

[Colin Walters <walters src gnome org>]

commit 7764799e356fb482f732e3a248e22d69d5e4d86b
Author: Colin Walters <walters verbum org>
Date:   Sun Jan 15 16:49:07 2012 -0500

    build: Add --disable-documentation
    
    Documentation is the source of many cyclical build loops.  Allow
    operating system builders to manually cut these cycles initially
    by disabling documentation for a first pass.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=675087

 Makefile.am  |    6 ++++--
 configure.ac |    4 ++++
 2 files changed, 8 insertions(+), 2 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index f522f40..c180854 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -4,12 +4,14 @@ SUBDIRS = 			\
 	data			\
 	common 			\
 	daemon 			\
-	docs			\
 	gui 			\
 	utils 			\
 	po 			\
 	tests 			\
 	$(NULL)
+if ENABLE_DOCUMENTATION
+SUBDIRS += docs
+endif
 
 # add these when help gets added back
 # omf-install
@@ -27,6 +29,6 @@ DISTCLEANFILES = \
 	gnome-doc-utils.make	\
 	$(NULL)
 
-DISTCHECK_CONFIGURE_FLAGS = --disable-scrollkeeper --enable-split-authentication --enable-introspection
+DISTCHECK_CONFIGURE_FLAGS = --disable-scrollkeeper --enable-split-authentication --enable-introspection --enable-documentation
 
 distuninstallcheck_listfiles = find . -type f -print | grep -v '^\./var/scrollkeeper'
diff --git a/configure.ac b/configure.ac
index c35ad8c..35e6e04 100644
--- a/configure.ac
+++ b/configure.ac
@@ -44,6 +44,10 @@ AC_CONFIG_MACRO_DIR([m4])
 IT_PROG_INTLTOOL([0.40.0])
 
 GNOME_DOC_INIT
+AC_ARG_ENABLE([documentation],
+	AS_HELP_STRING([--enable-documentation], [enable man pages and HTML documentation]),
+	[], [enable_documentation=yes])
+AM_CONDITIONAL(ENABLE_DOCUMENTATION, test x$enable_documentation = xyes)
 
 GETTEXT_PACKAGE=gdm
 AC_SUBST(GETTEXT_PACKAGE)