[alacarte] Generate the ChangeLog from git log

[Cosimo Cecchi <cosimoc src gnome org>]

commit 156cd7f59a3ef413423cbb0cd72f2ccc72f3b1ea
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Mon May 4 15:54:04 2009 +0200

    Generate the ChangeLog from git log
---
 ChangeLog => ChangeLog.pre-git |    0
 Makefile.am                    |   22 +++++++++++++++++++++-
 2 files changed, 21 insertions(+), 1 deletions(-)

diff --git a/ChangeLog b/ChangeLog.pre-git
similarity index 100%
rename from ChangeLog
rename to ChangeLog.pre-git
diff --git a/Makefile.am b/Makefile.am
index 880d2cc..997ac0e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -13,4 +13,24 @@ alacarte: alacarte.in
 	    < $< > $@
 alacarte: Makefile
 
-EXTRA_DIST = alacarte.in
+EXTRA_DIST = \
+	alacarte.in \
+	MAINTAINERS \
+	ChangeLog.pre-git
+
+ChangeLog:
+	@echo Creating $@
+	@if test -d "$(srcdir)/.git"; then \
+	  (GIT_DIR=$(top_srcdir)/.git ./missing --run git log git-migration.. --stat -M -C --name-status  --date=short --no-color) | fmt --split-only > $  tmp \
+	  && mv -f $  tmp $@ \
+	  || ($(RM) $  tmp; \
+	      echo Failed to generate ChangeLog, your ChangeLog may be outdated >&2; \
+	      (test -f $@ || echo git-log is required to generate this file >> $@)); \
+	else \
+	  test -f $@ || \
+	  (echo A git checkout and git-log is required to generate ChangeLog >&2 && \
+	   echo A git checkout and git-log is required to generate this file >> $@); \
+	fi
+
+.PHONY: ChangeLog
+