Re: [PATCH 2/2] git-rebase: error out when incompatible options passed

> 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!