[libgd] build: don't always rebuild .vapi file

[Christophe Fergeau <teuf src gnome org>]

commit 16cc32dd2d6837d24efcf16d3af94a9ac53172ff
Author: Christophe Fergeau <cfergeau redhat com>
Date:   Mon Sep 3 12:16:19 2012 +0200

    build: don't always rebuild .vapi file
    
    vapigen not touching nor overwrite the dest file if its content hasn't
    changed. This causes the rule to generate the .vapi file to always trigger
    as it will always be older than the .gir file which is generated
    during the build. Workaround this issue by touching the .vapi file
    after generating it.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=683257

 Makefile.am |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index a4f9f0a..dcbb849 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -165,6 +165,10 @@ $(srcdir)/gd-1.0.vapi: $(srcdir)/Gd-1.0.gir
 		--library gd-1.0		\
 		--pkg gtk+-3.0			\
 		$<
+#This 'touch' is a workaround for vapigen not touching the dest file if
+#its content hasn't changed, which causes the rule to generate the .vapi
+#file to always trigger
+	@touch $@
 
 noinst_DATA += $(VAPIS)
 EXTRA_DIST += $(VAPIS)