Hi Simon, Bruno, and Paul,
Following this thread from a few months ago [1]. Simon wanted to change
'git-log-to-changelog' so it used dates based on UTC time.
But Bruno said:
> I don't agree with this patch. It misrepresents the dates on which people
> have checked in their commits.
[...]
> There was a problem already before, in gitlog-to-changelog. Namely, what
> if a committer sits in California and the release manager, who creates the
> tarball, sits in England or Germany? The same effect as above would occur.
> But your change now made it even worse: Even the release manager cannot
> override the time zone.
> The real fix, IMO, is to use 'git log --format=fuller', and convert
> the CommitDate (*) by removing the time zone. In the example above:
> CommitDate: Sat Mar 16 22:29:02 2024 -0700
> -> 2024-03-16
and then Paul added:
> Emacs has had the tradition of using UTC for ChangeLog dates, so
> please support that as well, as an option.
I've attached a patch that I think deals with these issues. Can you all
look over it for me?
The patch adds a new '--utc' option and changes the default behavior so
that localtime is no longer used. The default behavior invokes git with
options to output ISO 8601 time. For example:
[commit-hash]:2024-07-02T20:08:08+02:00 Bruno Haible <br...@clisp.org>
git-merge-changelog: Simplify installation instructions.
That way we can just trim off the time and offset and use the date. When
using '--utc' we can use gmtime like Simon did with his patch.
Let me know if this is okay and I can commit it with documentation
adjustments. BTW, I don't know the time functions very well so there is
probably a better way to do this...
Collin
[1] https://lists.gnu.org/archive/html/bug-gnulib/2024-04/msg00188.html
>From f4ad3c9376a23e10890e1db23e2f28270848f4d2 Mon Sep 17 00:00:00 2001
From: Collin Funk <collin.fu...@gmail.com>
Date: Wed, 3 Jul 2024 05:25:54 -0700
Subject: [PATCH] gitlog-to-changelog: Improve handling of time zones.
* build-aux/gitlog-to-changelog: Use the commit date in the committers
timezone by default. Add the --utc option to convert commit times to UTC
before using the date.
(usage): Mention the --utc option.
---
ChangeLog | 8 ++++++++
build-aux/gitlog-to-changelog | 27 +++++++++++++++++++++++----
2 files changed, 31 insertions(+), 4 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index fcef360b22..aca200cc13 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2024-07-03 Collin Funk <collin.fu...@gmail.com>
+
+ gitlog-to-changelog: Improve handling of time zones.
+ * build-aux/gitlog-to-changelog: Use the commit date in the committers
+ timezone by default. Add the --utc option to convert commit times to UTC
+ before using the date.
+ (usage): Mention the --utc option.
+
2024-07-02 Bruno Haible <br...@clisp.org>
git-merge-changelog: Simplify installation instructions.
diff --git a/build-aux/gitlog-to-changelog b/build-aux/gitlog-to-changelog
index 49e7ef95ce..d92eb621da 100755
--- a/build-aux/gitlog-to-changelog
+++ b/build-aux/gitlog-to-changelog
@@ -97,6 +97,7 @@ OPTIONS:
--strip-cherry-pick remove data inserted by "git cherry-pick";
this includes the "cherry picked from commit ..." line,
and the possible final "Conflicts:" paragraph.
+ --utc convert commit times to UTC before extracting the date
--help display this help and exit
--version output version information and exit
@@ -247,6 +248,7 @@ sub git_dir_option($)
my $ignore_line;
my $strip_tab = 0;
my $strip_cherry_pick = 0;
+ my $utc_commit_time = 0;
my $srcdir;
GetOptions
(
@@ -262,6 +264,7 @@ sub git_dir_option($)
'ignore-line=s' => \$ignore_line,
'strip-tab' => \$strip_tab,
'strip-cherry-pick' => \$strip_cherry_pick,
+ 'utc' => \$utc_commit_time,
'srcdir=s' => \$srcdir,
) or usage 1;
@@ -274,10 +277,12 @@ sub git_dir_option($)
# that makes a correction in the log or attribution of that commit.
my $amend_code = defined $amend_file ? parse_amend_file $amend_file : {};
+ my $commit_time_format = $utc_commit_time ? '%ct' : '%cI';
my @cmd = ('git',
git_dir_option $srcdir,
qw(log --log-size),
- '--pretty=format:%H:%ct %an <%ae>%n%n'.$format_string, @ARGV);
+ ("--pretty=format:%H:$commit_time_format"
+ . ' %an <%ae>%n%n'.$format_string, @ARGV));
open PIPE, '-|', @cmd
or die ("$ME: failed to run '". quoted_cmd (@cmd) ."': $!\n"
. "(Is your Git too old? Version 1.5.1 or later is required.)\n");
@@ -350,17 +355,31 @@ sub git_dir_option($)
my $author_line = shift @line;
defined $author_line
or die "$ME:$.: unexpected EOF\n";
- $author_line =~ /^(\d+) (.*>)$/
+ $author_line =~ /^(\S+) (.*>)$/
or die "$ME:$.: Invalid line "
. "(expected date/author/email):\n$author_line\n";
+ # Author <email>
+ my $author = $2;
+
+ my $commit_date = $1;
+ if ($utc_commit_time)
+ {
+ # Seconds since the Epoch.
+ $commit_date = strftime "%Y-%m-%d", gmtime ($commit_date);
+ }
+ else
+ {
+ # ISO 8601 date.
+ $commit_date =~ s/T.*$//;
+ }
+
# Format 'Copyright-paperwork-exempt: Yes' as a standard ChangeLog
# '(tiny change)' annotation.
my $tiny = (grep (/^(?:Copyright-paperwork-exempt|Tiny-change):\s+[Yy]es$/, @line)
? ' (tiny change)' : '');
- my $date_line = sprintf "%s %s$tiny\n",
- strftime ("%Y-%m-%d", localtime ($1)), $2;
+ my $date_line = "$commit_date $author$tiny\n";
my @coauthors = grep /^Co-authored-by:.*$/, @line;
# Omit meta-data lines we've already interpreted.
--
2.45.2
