[vala] vala.m4: Fix calling VALA_CHECK_PACKAGES multiple times

[JÃrg Billeter <juergbi src gnome org>]

commit d6ef603fad9755b84b550780053917eb845c1eab
Author: Jens Georg <mail jensge org>
Date:   Thu May 3 19:36:37 2012 +0200

    vala.m4: Fix calling VALA_CHECK_PACKAGES multiple times
    
    If you call VALA_CHECK_PACKAGES more than once, each call would append
    its packages to the list of checked packages.
    
    Also fixes a leading whitespace error.
    
    Fixes bug 675389.

 vala.m4 |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/vala.m4 b/vala.m4
index 1d80ffa..79c32a1 100644
--- a/vala.m4
+++ b/vala.m4
@@ -42,10 +42,12 @@ _ACEOF
 #
 AC_DEFUN([VALA_CHECK_PACKAGES],
 [
+  unset vala_pkgs
+  unset vala_bindings
   ac_save_ifs="$IFS"; unset IFS
   for vala_pkg in $(echo "$1"); do
-      vala_pkgs="$vala_pkgs --pkg $vala_pkg"
-      vala_bindings="$vala_bindings $vala_pkg"
+      vala_pkgs="${vala_pkgs:+$vala_pkgs }--pkg $vala_pkg"
+      vala_bindings="${vala_bindings:+$vala_bindings }$vala_pkg"
   done
   IFS="$ac_save_ifs"
   AC_MSG_CHECKING([for $vala_bindings vala bindings])