Re: ChangeLogs in commit messages

[Gary Benson <gbenson at redhat dot com>]

Joel Brobecker wrote:
> >   1. With paths and with the date-and-author header:
> > 
> >     gdb/
> >     2014-07-30  Gary Benson  <gbenson@redhat.com>
> > 
> >             * btrace.c: Include defs.h.
> >             * common/ptid.c: Include defs.h or server.h as appropriate.
> >             * nat/mips-linux-watch.c: Likewise.
> > 
> >   2. With date-and-author headers but no paths:
> > 
> >     2014-08-04  Tom Tromey  <tromey@redhat.com>
> >       
> >             * gdb.base/sss-bp-on-user-bp-2.exp: Match "to_resume", not
> >             "target_resume".
> > 
> >   3. With paths but no date-and-author headers:
> > 
> >     gdb/ChangeLog:
> >       
> >             * amd64-windows-tdep.c (amd64_windows_frame_decode_insns):
> >               Add debug trace.
> > 
> >   4. With no preamble at all:
> > 
> >             * chew.c (print_stack_level, main): Cast result of pointer
> >             difference to match format string.
> > 
> > What are people's preferences here?  My preference is #1, but I
> > could live with #3.  If we come to some kind of concensus on this
> > I'll update the wiki to reflect this.
> 
> #3, since date and author are often redundant with the commit's
> author. And even if not in the same, it's in the ChangeLog entry
> that should be checked in as part of the commit. Also, I feel like
> having those in the CL is an extra source of potential issue (eg:
> if forgot to update the date), and revision logs cannot be fixed
> once the commit has been pushed, whereas dates in ChangeLog entries
> can.

My concern with omitting the author-and-date is for commits with
multiple authors, and/or multiple commits that have been squashed
with git-rebase (which uses the date and author of the commit that
was "pick"ed rather than that of other commits that were "squash"ed
or "fixup"ed into it.  For example:

  commit 314c6a3559393741f22fdd9836f83d9f364fbd2a
  Author: Tom Tromey <tromey@redhat.com>
  Date:   Fri Jun 13 09:22:09 2014 -0600

      Make gdbserver CORE_ADDR unsigned
    
      gdbserver defines CORE_ADDR to be signed.  This seems erroneous to
      me; and furthermore likely to cause problems in common/, as it is
      different from gdb's definition.
    
      gdb/gdbserver/
      2014-07-24  Tom Tromey  <tromey@redhat.com>
                  Gary Benson  <gbenson@redhat.com>
    
              * server.h (CORE_ADDR): Now unsigned.

This commit came from a half-finished branch Tom started back in
January.  I picked it up June or so, updated/tidied it a bit and
submitted it for review.  It was pushed on July 24 but the date on
the commit is June 13.  I think most people use rebase eventually,
so this kind of thing is pretty common.  The multiple authors
things is less common but not unique.

Thanks,
Gary

-- 
http://gbenson.net/