From a0bdd9af01174e4f0e39b9487ab7be61ac625ff4 Mon Sep 17 00:00:00 2001
From: Clint Byrum <clint@fewbar.com>
Date: Sun, 25 Sep 2016 00:43:45 -0700
Subject: [PATCH] Generate ChangeLog in make dist

We don't need to hand-roll this, as we've already recorded this in the
git changelog.
---
 ChangeLog                   |  3 ++
 Makefile.am                 |  4 ++
 configure.ac                |  2 +
 m4/ax_generate_changelog.m4 | 99 +++++++++++++++++++++++++++++++++++++
 4 files changed, 108 insertions(+)
 create mode 100644 m4/ax_generate_changelog.m4

diff --git a/ChangeLog b/ChangeLog
index 086f4a810..e9b478351 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,6 @@
+This is the hand-created ChangeLog used prior to v1.1.3. Please refer to git
+log for changes after that.
+
 1.1.12 Sun Feb  9 04:27:38 PST 2014
 * GEARMAN_SERVERS environmental variable for libgearman to pick up servers to
 communicate with. This means that any driver now linked with libgearman will
diff --git a/Makefile.am b/Makefile.am
index e728b178a..56d4b51f6 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -60,6 +60,10 @@ include support/include.am
 include m4/include.am
 include rpm/include.mk
 
+@GENERATE_CHANGELOG_RULES@
+CHANGELOG_GIT_FLAGS = --date=short --pretty=tformat:"%+D - %ad %s" --no-merges
+dist-hook: dist-ChangeLog
+
 TESTS += $(bin_PROGRAMS)
 TESTS += $(check_PROGRAMS)
 XFAIL_TESTS += $(bin_PROGRAMS)
diff --git a/configure.ac b/configure.ac
index 6ca09f983..2f3afa6d8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -25,6 +25,8 @@ AC_CANONICAL_HOST
 AC_ARG_PROGRAM
 AC_USE_SYSTEM_EXTENSIONS
 
+AX_GENERATE_CHANGELOG
+
 AM_INIT_AUTOMAKE([1.11 color-tests -Wno-portability subdir-objects foreign tar-ustar])
 
 AC_CONFIG_HEADERS([gear_config.h:gear_config.in])dnl Keep filename to 8.3 for MS-DOS.
diff --git a/m4/ax_generate_changelog.m4 b/m4/ax_generate_changelog.m4
new file mode 100644
index 000000000..d9d5cd105
--- /dev/null
+++ b/m4/ax_generate_changelog.m4
@@ -0,0 +1,99 @@
+# ===========================================================================
+#   http://www.gnu.org/software/autoconf-archive/ax_generate_changelog.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_GENERATE_CHANGELOG()
+#
+# DESCRIPTION
+#
+#   Builds a rule for generating a ChangeLog file from version control
+#   system commit messages.  Currently, the only supported VCS is git, but
+#   support for others could be added in future.
+#
+#   Defines GENERATE_CHANGELOG_RULES which should be substituted in your
+#   Makefile.
+#
+#   Usage example:
+#
+#   configure.ac:
+#
+#     AX_GENERATE_CHANGELOG
+#
+#   Makefile.am:
+#
+#     @GENERATE_CHANGELOG_RULES@
+#     CHANGELOG_START = 0.2.3^
+#     dist-hook: dist-ChangeLog
+#
+#   ChangeLog (stub committed to VCS):
+#
+#     The ChangeLog is auto-generated when releasing.
+#     If you are seeing this, use 'git log' for a detailed list of changes.
+#
+#   This results in a "dist-ChangeLog" rule being added to the Makefile.
+#   When run, "dist-ChangeLog" will generate a ChangeLog in the
+#   $(top_distdir), using $(CHANGELOG_GIT_FLAGS) to format the output from
+#   "git log" being run in $(CHANGELOG_GIT_DIR).
+#
+#   Unless Automake is initialised with the 'foreign' option, a dummy
+#   ChangeLog file must be committed to VCS in $(top_srcdir), containing the
+#   text above (for example).  It will be substituted by the automatically
+#   generated ChangeLog during "make dist".
+#
+# LICENSE
+#
+#   Copyright (c) 2015 David King <amigadave@amigadave.com>
+#   Copyright (c) 2015 Philip Withnall <philip.withnall@collabora.co.uk>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved.  This file is offered as-is, without any
+#   warranty.
+
+#serial 1
+
+AC_DEFUN([AX_GENERATE_CHANGELOG],[
+	# Find git, defaulting to the 'missing' script so the user gets a nice
+	# message if git is missing, rather than a plain 'command not found'.
+	AC_PATH_PROG([GIT],[git],[${am_missing_run}git])
+	AC_SUBST([GIT])
+
+	# Build the ChangeLog rules.
+	m4_pattern_allow([AM_V_GEN])
+GENERATE_CHANGELOG_RULES='
+# Generate ChangeLog
+#
+# Optional:
+#  - CHANGELOG_START: git commit ID or tag name to output changelogs from
+#    (exclusive). (Default: include all commits)
+#  - CHANGELOG_GIT_FLAGS: General flags to pass to git-log when generating the
+#    ChangeLog. (Default: various)
+#  - CHANGELOG_GIT_DIR: .git directory to use. (Default: $(top_srcdir)/.git)
+
+# git-specific
+CHANGELOG_GIT_FLAGS ?= --stat -M -C --name-status --no-color
+CHANGELOG_GIT_DIR ?= $(top_srcdir)/.git
+
+ifeq ($(CHANGELOG_START),)
+CHANGELOG_GIT_RANGE =
+else
+CHANGELOG_GIT_RANGE = $(CHANGELOG_START)..
+endif
+
+# Generate a ChangeLog in $(top_distdir)
+dist-ChangeLog:
+	$(AM_V_GEN)if $(GIT) \
+		--git-dir=$(CHANGELOG_GIT_DIR) --work-tree=$(top_srcdir) log \
+		$(CHANGELOG_GIT_FLAGS) $(CHANGELOG_GIT_RANGE) \
+		| fmt --split-only >.ChangeLog.tmp; \
+	then mv -f .ChangeLog.tmp "$(top_distdir)/ChangeLog"; \
+	else rm -f .ChangeLog.tmp; exit 1; fi
+
+.PHONY: dist-ChangeLog
+'
+
+	AC_SUBST([GENERATE_CHANGELOG_RULES])
+	m4_ifdef([_AM_SUBST_NOTMAKE], [_AM_SUBST_NOTMAKE([GENERATE_CHANGELOG_RULES])])
+])