Generate a ChangeLog file from commit logs

* .gitignore: Add 'ChangeLog'.
* build-aux/gitlog-to-changelog: New file, from Gnulib.
* build-aux/gitlog-to-emacslog: New file.
* CONTRIBUTE: Document the revised workflow.
* Makefile.in (clean): Remove *.tmp and etc/*.tmp*
instead of just special cases.
(CHANGELOG_HISTORY_INDEX_MAX, CHANGELOG_N, gen_origin): New vars.
(ChangeLog, unchanged-history-files, change-history)
(change-history-commit): New rules.
* admin/admin.el (make-manuals-dist--1):
Don't worry about doc/ChangeLog.
* admin/authors.el: Add a FIXME.
* admin/make-tarball.txt:
* lisp/calendar/icalendar.el:
* lisp/gnus/deuglify.el:
* lisp/obsolete/gulp.el:
* lwlib/README:
Adjust to renamed ChangeLog history files.
* admin/merge-gnulib (GNULIB_MODULES): Add gitlog-to-changelog.
* admin/notes/repo: Call it 'master' a la Git, not 'trunk' a la Bzr.
Remove obsolete discussion of merging ChangeLog files.
New section "Maintaining ChangeLog history".
* build-aux/git-hooks/pre-commit:
Reject attempts to commit files named 'ChangeLog'.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* make-dist: Make and distribute top-level ChangeLog if there's a
.git directory.  Distribute the new ChangeLog history files
instead of scattered ChangeLog files.  Distribute the new files
gitlog-to-changelog and gitlog-to-emacslog.
Fixes: bug#19113

1 files changed, 10 insertions, 8 deletions

diff --git a/build-aux/git-hooks/pre-commit b/build-aux/git-hooks/pre-commit
index d050c40a2e6..8bce1f5ade0 100755
--- a/build-aux/git-hooks/pre-commit
+++ b/build-aux/git-hooks/pre-commit
@@ -34,13 +34,15 @@ if test "$nbadchars" -ne 0; then
   exit 1
 fi
 
-new_names=`$git_diff HEAD` || exit
-case "
-$new_names" in
-  */-* | *'
-'-*)
-    echo "File name component begins with '-'."
-    exit 1;;
-esac
+for new_name in `$git_diff HEAD`; do
+  case $new_name in
+    -* | */-*)
+      echo "$new_name: File name component begins with '-'."
+      exit 1;;
+    ChangeLog | */ChangeLog)
+      echo "$new_name: Please use git commit messages, not ChangeLog files."
+      exit 1;;
+  esac
+done
 
 exec git diff-index --check --cached HEAD --