Rework ChangeLog generation to fix make distcheck
diff --git a/Makefile.am b/Makefile.am
index b9b9188..55bdaa6 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -106,7 +106,23 @@
-dist-hook: ChangeLog
+distclean-local:
+ if test "$(srcdir)" = "."; then :; else \
+ rm -f ChangeLog; \
+ fi
-ChangeLog : .git/HEAD
- $(AM_V_GEN) git log --stat > ChangeLog
+ChangeLog:
+ $(AM_V_GEN) if test -d "$(srcdir)/.git"; then \
+ (GIT_DIR=$(top_srcdir)/.git ./missing --run git log --stat) | 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+ echo Failed to generate ChangeLog, your ChangeLog may be outdated 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
+
