maint: generate full and correct ChangeLog.

* gnulib: Updated to pick up gitlog-to-changelog multi-author
support.
* gl/build-aux/gitlog-to-changelog.diff: Use gnulib-rejected
patch for '(tiny change)' support.
* Makefile.am (ChangeLog): Use gitlog-to-changelog --amend=F
option.
* libltdl/config/git-hooks/commit-msg: New commit message hook
for git.
* libltdl/config/git-log-fix: New file, with ChangeLog fixes.
* HACKING (Using git): Update.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>

6 files changed, 245 insertions, 11 deletions

diff --git a/HACKING b/HACKING
index 21a810b3..8f83f1a3 100644
--- a/HACKING
+++ b/HACKING
@@ -92,15 +92,30 @@ and is not part of a release distribution.
 5. Using git
 ============
 
-* Preferably, let the git commit message mirror the ChangeLog entry,
-  without the leading TABs.  Use --author for the (first, main) author
-  of patches from others, sign patches you have reviewed.  If the
-  ChangeLog entry is longer than a line, use a one line summary, then an
-  empty line, then the rest of the log entry; this makes for nice output
-  of `git log'.
-
-* You may find it useful to install the git-merge-changelog merge driver:
-  <http://git.sv.gnu.org/gitweb/?p=gnulib.git;a=blob;f=lib/git-merge-changelog.c>
+* ChangeLog is generated from git log messages, so you have to format
+  the git log carefully.  Use --author for the (first, main) author
+  of changesets from others, and sign patches you have reviewed.  If the
+  changeset has additional authors that need to be mentioned in the
+  generated ChangeLog, then add them to the git log message with:
+
+    Co-authored-by: A U Thor <email@example.com>
+
+  Similarly, if the ChangeLog will need a '(tiny change)' annotation,
+  then you should indicate that in the git log message with:
+
+    Copyright-paperwork-exempt: Yes
+
+  Start the git log message with a short one line summary, then an empty
+  line, then the rest of the log entry.
+
+  If you forgot to annotate correctly in the git log message, or made
+  any other mistake that needs correcting in the distributed ChangeLog
+  file, make an amendment against the SHA1 of the errored commit in
+  $aux_dir/git-log-fix.
+
+* You may find it useful to install the $aux_dir/git-hooks/commit-msg
+  script to .git/hooks in your libtool working directory to help you
+  make the best use of git log message metadata.
 
 * Do not ever rewind the public master branch nor any public release
   branch on savannah, neither any release tags once they have been
diff --git a/Makefile.am b/Makefile.am
index 803d6692..ab6a1066 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -532,6 +532,7 @@ install-data-local: $(lt_Makefile_in)
 
 edit_readme_alpha	= $(srcdir)/$(aux_dir)/edit-readme-alpha
 gitlog_to_changelog	= $(srcdir)/$(aux_dir)/gitlog-to-changelog
+git_log_fix		= $(srcdir)/$(aux_dir)/git-log-fix
 
 dotserial		= $(distdir)/.serial
 dotversion		= $(srcdir)/.version
@@ -543,8 +544,9 @@ changelog		= $(distdir)/ChangeLog
 # date is updated to the following year.
 changelog_start_date = 2011-01-01
 $(changelog): FORCE
-	$(AM_V_GEN)if test -d .git; then \
-	  $(gitlog_to_changelog) --since=$(changelog_start_date) > '$@T'; \
+	$(AM_V_GEN)if test -d $(srcdir)/.git; then \
+	  $(gitlog_to_changelog) --amend=$(git_log_fix) \
+	      --since=$(changelog_start_date) > '$@T'; \
 	  rm -f '$@'; mv '$@T' '$@'; \
 	fi
 
diff --git a/gl/build-aux/gitlog-to-changelog.diff b/gl/build-aux/gitlog-to-changelog.diff
new file mode 100644
index 00000000..57ed4c50
--- /dev/null
+++ b/gl/build-aux/gitlog-to-changelog.diff
@@ -0,0 +1,26 @@
+--- gnulib/build-aux/gitlog-to-changelog	2011-11-17 12:22:02.000000000 +0700
++++ gl/build-aux/gitlog-to-changelog	2011-11-17 12:19:01.000000000 +0700
+@@ -251,6 +251,11 @@
+ 
+       my $date_line = sprintf "%s  $2\n", strftime ("%F", localtime ($1));
+ 
++      # Format 'Copyright-paperwork-exempt: Yes' as a standard ChangeLog
++      # `(tiny change)' annotation.
++      my $tiny_change = grep /^Copyright-paperwork-exempt:\s+[Yy]es$/, @line;
++      $date_line =~ s/$/  (tiny change)/ if $tiny_change;
++
+       # Format 'Co-authored-by: A U Thor <email@example.com>' lines in
+       # standard multi-author ChangeLog format.
+       my @coauthors = grep /^Co-authored-by:.*$/, @line;
+@@ -277,9 +282,10 @@
+       $prev_date_line = $date_line;
+       @prev_coauthors = @coauthors;
+ 
+-      # Omit "Co-authored-by..." and "Signed-off-by..." lines.
++      # Omit meta-data lines we've already interpreted.
+       @line = grep !/^Signed-off-by: .*>$/, @line;
+       @line = grep !/^Co-authored-by: /, @line;
++      @line = grep !/^Copyright-paperwork-exempt: /, @line;
+ 
+       # Remove leading and trailing blank lines.
+       if (@line)
diff --git a/gnulib b/gnulib
-Subproject fb6de052bace5b26346c1624b57d87326a97c7b
+Subproject f51babfaf400eb509f854cad509f5e649b9182b
diff --git a/libltdl/config/git-hooks/commit-msg b/libltdl/config/git-hooks/commit-msg
new file mode 100755
index 00000000..620ee77f
--- /dev/null
+++ b/libltdl/config/git-hooks/commit-msg
@@ -0,0 +1,111 @@
+#!/bin/sh
+# An example hook script for catching duplicate or malformed
+# Co-authored-by or Copyright-paperwork-exempt lines in the
+# commit message.
+
+: ${SED="sed"}
+test set = ${ECHO+'set'} = set || ECHO='printf %s\n'
+
+basename="$SED -e "'s|^.*/||'
+
+nl='
+'
+
+progpath="$0"
+progname=`$ECHO "$progpath" |$basename`
+
+log_file=$1
+export log_file
+
+fn_error ()
+{
+    prefix="$progname: error: "
+
+    save_IFS=$IFS
+    IFS=$nl
+    for line in $*; do
+      IFS=$save_IFS
+      $ECHO "$prefix$line" 1>&2
+      prefix="$progname:        "
+    done
+    IFS=$save_IFS
+}
+
+fn_re_edit ()
+{
+    $ECHO 'Press return to edit. Ctrl-C to abort...' >&2
+    read v
+    ${EDITOR-'vi'} "$log_file"
+}
+
+fn_rewrite ()
+{
+    # Output once to stderr
+    fn_error "$*"
+
+    # And again as a comment in the log_file ready for re-editing
+    $ECHO "$*" |$SED 's,^,# ,'
+    echo
+    cat "$log_file"
+}
+
+fn_check_msg ()
+{
+    return_status=0
+
+    CAB_re='^Co-authored-by: '
+    CPR_re='^Copyright-paperwork-exempt: '
+
+    # Flag duplicated Co-authored-by lines.
+    dups=`grep "$CAB_re" "$log_file" 2>/dev/null \
+        |sort |uniq -c |sed -e '/^[	 ]*1[	 ]/d'`
+
+    test -n "$dups" && {
+	$ECHO 'Duplicate Co-authored-by lines:
+'"$dups"
+	return_status=1
+    }
+
+    # Make sure each Co-authored-by line contains a valid email.
+    email_re='<.*@.*\..*>'
+
+    grep "$CAB_re" "$log_file" 2>/dev/null \
+        |while read CAB; do
+            test 0 -eq `expr "$CAB" : ".*$email_re"` && {
+                echo "Malformed or missing email in \`$CAB'"
+	        return_status=1
+            }
+         done
+
+    # Flag duplicated Copyright-paperwork-exempt lines.
+    count=`grep "$CPR_re" "$log_file" 2>/dev/null \
+      |wc |sed -e 's,^[	 ]*,,;s,[ 	].*$,,'`
+
+    test 2 -gt "$count" || {
+      $ECHO 'More than one Copyright-paperwork-exempt line.'
+      return_status=1
+    }
+
+    # Make sure Copyright-paperwork-exempt line is valid.
+    if grep "${CPR_re}[Nn]" "$log_file" >/dev/null 2>&1; then
+      $ECHO "\
+\`Copyright-paperwork-exempt: No' is redundant, please remove."
+      return_status=1
+    else
+      not_yes=`grep "${CPR_re}" "$log_file" 2>/dev/null \
+        |grep -v "${CPR_re}Yes\$"`
+
+      test -n "$not_yes" && {
+        $ECHO "\`Copyright-paperwork-exempt' setting must be \`Yes'."
+        return_status=1
+      }
+    fi
+
+    return $return_status
+}
+
+while :; do
+    err=`fn_check_msg` && break
+    fn_rewrite "$err" > "${log_file}T" && mv "${log_file}T" "$log_file"
+    fn_re_edit
+done
diff --git a/libltdl/config/git-log-fix b/libltdl/config/git-log-fix
new file mode 100644
index 00000000..e03fe48d
--- /dev/null
+++ b/libltdl/config/git-log-fix
@@ -0,0 +1,80 @@
+# This file is expected to be used via gitlog-to-changelog's --amend=FILE
+# option.  It specifies what changes to make to each given SHA1's commit
+# log and metadata, using Perl-eval'able expressions.
+
+a5ef08182ce0fb80b8adcff5872f190afd915908
+# Date:   Wed Nov 16 12:13:55 2011 +0700
+# Fix a typo.
+s,bootstraps,bootstrap's,
+
+88224124e4f57166cdcc78be29730372762a147e
+# Date:   Tue Nov 15 16:44:15 2011 +0700
+# Fix a typo.
+s,todays,today's,
+
+e8db92c345b99acd9c6984a321fc241ed1d01d23
+# Date:   Tue Nov 15 13:26:53 2011 +0700
+# Email address of Reporters is in THANKS.
+s,(Reported by .*?) *<.*>,$1.,
+
+0fe4d0740effaec9d08ee9683fb493d8ad0bd8b5
+# Date:   Mon Oct 17 16:43:18 2011 +0700
+# No empty lines in a single commit.
+s,\n\n,\n,g;
+# Fix a typo.
+s,soure,source,
+
+789817d512111d063981446efc7493ce87696bb3
+# Date:   Mon Oct 17 12:40:55 2011 +0700
+# No empty lines in a single commit.
+s,\n\n,\n,g
+
+49ae2888b43cad358e2ff60a69722341116e7b40
+# Date:   Sun Oct 2 10:02:18 2011 -0500
+# No leading tabs in git log message.
+s,\n\t,\n,g
+
+920da81be698974faa50bd36a60248e2c18c4fd5
+# Date:   Sun Sep 25 17:39:04 2011 -0500
+# No leading tabs in git log message.
+s,\n\t,\n,g;
+# No empty lines in a single commit.
+s,\n\n,\n,g
+
+dc28c2bfbcb4879bc04a73186d72ec0e7ef2ad4c
+# Date:   Thu Sep 1 18:45:03 2011 -0500
+# Typo in name.
+s,Davd,David,
+
+1ea9302bd1eadf25b466fcd7e8697e4bef111493
+# Date:   Sun Apr 10 10:17:21 2011 +0200
+# Add back missing annotation:
+s,$,\nCopyright-paperwork-exempt: Yes,
+
+1b76054f4763a28ae1b01fbeee86ba0c524d1923
+# Date:   Mon Mar 14 08:40:50 2011 +0100
+# Refill to 64 columns (72 in ChangeLog including leading \t):
+s,to add all\nnecessary,to\nadd all necessary,;
+s,support\. Currently,support.\nCurrently,;
+s,filters\n,filters ,;
+s,the case with,the\ncase with,;
+s,This change\nhandles,This change handles,;
+s,the situation for,the situation\nfor,;
+s,thread\nsupport was,thread support\nwas,;
+# Indent urls slightly:
+s,\nhttp://,\n  http://,g;
+# No empty lines in a single commit:
+s,\n\n,\n,g;
+# Add back missing annotation, and co-author:
+s,$,\nCopyright-paperwork-exempt: Yes,;
+s,$,\nCo-authored-by: Rhys Ulerich <rhys.ulerich\@gmail.com>,;
+
+e94c6d6e0359d92f08f491f57e0ef3371e978952
+# Date:   Thu Jan 20 19:35:14 2011 +0100
+# Add back missing annotation:
+s,$,\nCopyright-paperwork-exempt: Yes,
+
+9167aecabd12c5afe7a65d45dc73f8c92ab42f05
+# Date:   Sun Jan 9 19:51:28 2011 +0100
+# Add back missing annotation:
+s,$,\nCopyright-paperwork-exempt: Yes,