[gnome-common] macros2: Add support for APPSTREAM_XML macro

[Bastien Nocera <hadess src gnome org>]

commit b23a0e022cde3e3aff15175bd5923eab17f48918
Author: Bastien Nocera <hadess hadess net>
Date:   Thu Sep 11 20:36:13 2014 +0200

    macros2: Add support for APPSTREAM_XML macro
    
    And request that appstream-xml.m4 get installed if missing.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=736497

 macros2/gnome-autogen.sh |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/macros2/gnome-autogen.sh b/macros2/gnome-autogen.sh
index fe1c8e7..28ee66d 100644
--- a/macros2/gnome-autogen.sh
+++ b/macros2/gnome-autogen.sh
@@ -284,6 +284,10 @@ for configure_ac in $configure_files; do
         require_m4macro appdata-xml.m4
     fi
 
+    if grep "^APPSTREAM_XML" $configure_ac >/dev/null; then
+        require_m4macro appstream-xml.m4
+    fi
+
     # check to make sure gnome-common macros can be found ...
     if grep "^GNOME_COMMON_INIT" $configure_ac >/dev/null ||
        grep "^GNOME_DEBUG_CHECK" $configure_ac >/dev/null ||