From 02c94c5f947854e94b1748837dc7277cd1106806 Mon Sep 17 00:00:00 2001
From: Nick Bowler <nbowler@draconx.ca>
Date: Wed, 28 Sep 2011 20:03:35 -0400
Subject: [PATCH] Update timestamps on generated header files before
 distributing them.

Otherwise we risk breaking VPATH builds from the tarball, as make may
attempt to regenerate the headers.
---
 Makefile.am | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Makefile.am b/Makefile.am
index 7c2099b..de6c066 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -120,6 +120,15 @@ uninstall-mo:
 src/scan.c src/scan.h: src/scan.stamp
 src/parse.c src/parse.h: src/parse.stamp
 
+# The flex/bison rules refrain from updating unchanged headers for the
+# convenience of developers, but the headers must be distributed with
+# up-to-date timestamps, otherwise make will try to update them in a fresh
+# VPATH build.
+dist-hook: update-headers
+update-headers:
+	touch -c '$(distdir)/src/scan.h'
+	touch -c '$(distdir)/src/parse.h'
+
 # Supporting rules for bison/flex.
 
 BISON_V   = $(BISON_V_$(V))
-- 
2.43.2