From: Elijah Newren <newren@gmail.com>
Date: Mon, 11 Jun 2018 15:19:49 GMT
Subject: Re: [PATCH 2/2] git-rebase: error out when incompatible options passed
Message-ID: <CABPp-BG7sR6NvHf4=ZOwxRh-KKR8QEVwB=D5p9DE_h1oDgRvoA@mail.gmail.com>
In-Reply-To: <cec770a8-28ee-d546-8c27-905d2fcdb0c8@talktalk.net>

Hi Phillip

On Sun, Jun 10, 2018 at 12:40 PM, Phillip Wood
<phillip.wood@talktalk.net> wrote:

>>   Documentation/git-rebase.txt           | 15 +++++++++++++--
>>   git-rebase.sh                          | 17 +++++++++++++++++
>>   t/t3422-rebase-incompatible-options.sh | 10 +++++-----
>>   3 files changed, 35 insertions(+), 7 deletions(-)
>>
>> diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
>> index 0e20a66e73..451252c173 100644
>> --- a/Documentation/git-rebase.txt
>> +++ b/Documentation/git-rebase.txt
>> @@ -243,6 +243,10 @@ leave out at most one of A and B, in which case it
>> defaults to HEAD.
>>   --keep-empty::
>>         Keep the commits that do not change anything from its
>>         parents in the result.
>> ++
>> +This uses the `--interactive` machinery internally, and as such,
>> +anything that is incompatible with --interactive is incompatible
>> +with this option.
>>     --allow-empty-message::
>>         By default, rebasing commits with an empty message will fail.
>> @@ -324,6 +328,8 @@ which makes little sense.
>>         and after each change.  When fewer lines of surrounding
>>         context exist they all must match.  By default no context is
>>         ever ignored.
>> +       Incompatible with the --merge and --interactive options, or
>> +       anything that implies those options or their machinery.
>
>
> struct replay_opts has an allow_empty_message member so I'm not sure that's
> true.

I think you were confused by the way the patch broke up.  The jump to
line 328 means that this comment is about the -C option, not the
--allow-empty-message option.

However, I probably should add a comment next to the
--allow-empty-message option, to not the reverse is true, i.e. that
it's incompatible with am-based rebases.  (git-rebase--am.sh ignores
the allow_empty_message variable set in git-rebase.sh, unlike
git-rebase--interactive.sh and git-rebase--merge.sh)

>>   -f::
>>   --force-rebase::
>> @@ -355,13 +361,15 @@ default is `--no-fork-point`, otherwise the default
>> is `--fork-point`.
>>   --whitespace=<option>::
>>         These flag are passed to the 'git apply' program
>>         (see linkgit:git-apply[1]) that applies the patch.
>> -       Incompatible with the --interactive option.
>> +       Incompatible with the --merge and --interactive options, or
>> +       anything that implies those options or their machinery.
>
>
> I wonder if it is better just to list the incompatible options it might be a
> bit long but it would be nicer for the user than them having to work out
> which options imply --interactive.

That could work.  Would this be done at the end of the 'OPTIONS'
section of the manpage?  Should I create an 'INCOMPATIBLE OPTIONS'
section that follows the 'OPTIONS' section?

>>   --committer-date-is-author-date::
>>   --ignore-date::
>>         These flags are passed to 'git am' to easily change the dates
>>         of the rebased commits (see linkgit:git-am[1]).
>> -       Incompatible with the --interactive option.
>> +       Incompatible with the --merge and --interactive options, or
>> +       anything that implies those options or their machinery.
>>     --signoff::
>>         Add a Signed-off-by: trailer to all the rebased commits. Note
>> @@ -400,6 +408,9 @@ The `--rebase-merges` mode is similar in spirit to
>> `--preserve-merges`, but
>>   in contrast to that option works well in interactive rebases: commits
>> can be
>>   reordered, inserted and dropped at will.
>>   +
>> +This uses the `--interactive` machinery internally, but it can be run
>> +without an explicit `--interactive`.
>> ++
>
> Without more context it's hard to judge but I'm not sure this adds anything
> useful

Hmm, yeah.  I noted that --exec had similar wording, noted that
--preserve-merges had something along the same lines but as a warning,
and didn't see the similar wording for --rebase-merges -- I somehow
missed the paragraph right above where I added these lines.  Oops.
Anyway, I'll pull it out.

>>   It is currently only possible to recreate the merge commits using the
>>   `recursive` merge strategy; Different merge strategies can be used only
>> via
>>   explicit `exec git merge -s <strategy> [...]` commands.
>> diff --git a/git-rebase.sh b/git-rebase.sh
>> index 40be59ecc4..f1dbecba18 100755
>> --- a/git-rebase.sh
>> +++ b/git-rebase.sh
>> @@ -503,6 +503,23 @@ then
>>         git_format_patch_opt="$git_format_patch_opt --progress"
>>   fi
>>   +if test -n "$git_am_opt"; then
>> +       incompatible_opts=`echo "$git_am_opt" | sed -e 's/ -q//'`
>
>
> I think the style guide recommends $() over ``

Will fix.


Thanks for taking a look!

Elijah