[gnome-documents] build: Add --disable-documentation

[Colin Walters <walters src gnome org>]

commit b549d50c520cd1d34ff653997ad0892b0f2cb2d7
Author: Colin Walters <walters verbum org>
Date:   Fri Oct 18 15:22:43 2013 -0400

    build: Add --disable-documentation
    
    Since Continuous doesn't have Docbook.

 Makefile.am  |    5 ++++-
 configure.ac |   12 +++++++++++-
 2 files changed, 15 insertions(+), 2 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index 824785d..1c9380d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,6 +1,9 @@
 ACLOCAL_AMFLAGS = -I m4 -I libgd ${ACLOCAL_FLAGS}
 
-SUBDIRS = libgd src data man po
+SUBDIRS = libgd src data po
+if BUILD_DOCUMENTATION
+SUBDIRS += man
+endif
 
 if ENABLE_GETTING_STARTED
 
diff --git a/configure.ac b/configure.ac
index 8db8923..5c570b6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -58,7 +58,17 @@ TRACKER_MIN_VERSION=0.13.1
 ZAPOJIT_MIN_VERSION=0.0.2
 SOUP_MIN_VERSION=2.41.3
 
-AC_PATH_PROG([XSLTPROC], [xsltproc])
+AC_ARG_ENABLE(documentation,
+              AS_HELP_STRING([--enable-documentation],
+                             [build documentation]),,
+              enable_documentation=yes)
+if test x$enable_documentation = xyes; then
+   AC_PATH_PROG([XSLTPROC], [xsltproc])
+   if test x$XSLTPROC = x; then
+      AC_MSG_ERROR([xsltproc is required to build documentation])
+   fi
+fi
+AM_CONDITIONAL(BUILD_DOCUMENTATION, test x$enable_documentation = xyes)
 
 PKG_CHECK_MODULES(DOCUMENTS,
                   evince-document-3.0 >= $EVINCE_MIN_VERSION