[gnome-panel] build: Generate ChangeLog on make dist

[Vincent Untz <vuntz src gnome org>]

commit 3d0245ce1f0a6c47c6495e00e6e28945e82c8901
Author: Vincent Untz <vuntz gnome org>
Date:   Wed Feb 22 15:10:25 2012 +0100

    build: Generate ChangeLog on make dist

 Makefile.am |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index fd50fa2..8d10381 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -46,5 +46,18 @@ MAINTAINERCLEANFILES = \
 	$(srcdir)/m4/ltversion.m4 \
 	$(srcdir)/m4/lt~obsolete.m4
 
+CHANGELOG_GIT_RANGE = GNOME_PANEL_2_26_1..
+dist-hook:
+	$(AM_V_GEN)if test -d "$(srcdir)/.git"; then \
+	  ( echo '# Generated by Makefile. Do not edit.'; echo; \
+	    GIT_DIR="$(top_srcdir)/.git" ./missing --run \
+	    git log $(CHANGELOG_GIT_RANGE) --no-color -M -C --name-status ) \
+	  > ChangeLog.tmp \
+	  && mv -f ChangeLog.tmp $(distdir)/ChangeLog \
+	  || ( rm -f ChangeLog.tmp ; echo Failed to generate ChangeLog >&2 ); \
+	else \
+	  echo A git checkout is required to generate ChangeLog >&2; \
+	fi
+
 GITIGNOREFILES = $(PACKAGE)-\*.tar.{gz,bz2,xz}
 -include $(top_srcdir)/git.mk