[gnome-software] build: Add --enable-man, default to auto

[Colin Walters <walters src gnome org>]

commit 626ba59948d07e7c7253eabbd733cf5950989483
Author: Colin Walters <walters verbum org>
Date:   Wed Aug 28 16:17:10 2013 -0400

    build: Add --enable-man, default to auto
    
    This fixes the build in gnome-ostree which doesn't have docbook2man.

 configure.ac    |   15 ++++++++++++++-
 src/Makefile.am |    6 ++++--
 2 files changed, 18 insertions(+), 3 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index e48130a..156a9b5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -75,7 +75,20 @@ dnl ---------------------------------------------------------------------------
 PKG_CHECK_MODULES(GTK, gtk+-3.0 >= 3.9.12)
 PKG_CHECK_MODULES(PACKAGEKIT, packagekit-glib2 >= 0.8.10)
 PKG_CHECK_MODULES(SQLITE, sqlite3)
-AC_PATH_PROG(DOCBOOK2MAN, docbook2man)
+AC_ARG_ENABLE(man,
+              [AS_HELP_STRING([--enable-man],
+                              [generate man pages [default=auto]])],,
+              enable_man=maybe)
+AS_IF([test "$enable_man" != no], [
+  AC_PATH_PROG(DOCBOOK2MAN, docbook2man)
+  AS_IF([test -z "$DOCBOOK2MAN"], [
+    AS_IF([test "$enable_man" = yes], [
+      AC_MSG_ERROR([docbook2man is required for --enable-man])
+    ])
+    enable_man=no
+  ])
+])
+AM_CONDITIONAL(ENABLE_MAN, test "$enable_man" != no)
 
 dnl ---------------------------------------------------------------------------
 dnl - Makefiles, etc.
diff --git a/src/Makefile.am b/src/Makefile.am
index 3c0ce4a..1f8393a 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -108,8 +108,10 @@ EXTRA_DIST =                                               \
        $(desktop_in_files)                             \
        $(UI_FILES)
 
-man_MANS =                                             \
-       gnome-software.1
+man_MANS =
+if ENABLE_MAN
+man_MANS += gnome-software.1
+endif
 
 gnome-software.1: gnome-software.sgml
        docbook2man $? > /dev/null