Fwd: Unknown option for merge-recursive: -X'diff-algorithm=patience'

> Hello,
> 
> I am running git 2.15.1 and facing the following issue with linux kernel
> tree.
> 
> # git checkout v3.8
> # git branch abc-3.8
> # git checkout v3.9
> # git branch abc-3.9
> # git checkout abc-3.8
> 
> Introduce new commit on top of abc-3.8. Here, I edit README.
> 
> # vim README
> # git commit -a -v
> [abc-3.8 4bf088b5d341] Hello world
> 
> Then I try to rebase abc-3.9 on top of abc-3.8 as the following:
> 
> # git rebase --preserve-merges -s recursive -Xdiff-algorithm=patience
> --onto abc-3.8 v3.8 abc-3.9
> 
> And then I see:
> 
> fatal: Unknown option for merge-recursive: -X'diff-algorithm=patience'
> Error redoing merge e84cf5d0fd53badf3a93c790e280cc92a69ed999
> 
> Attached here is GIT_TRACE=1 output.
> 

> It seems there is some issue with double escaping:
> ...
>> # git rebase --preserve-merges -s recursive -Xdiff-algorithm=patience
>> --onto abc-3.8 v3.8 abc-3.9
>> 
>> And then I see:
>> 
>> fatal: Unknown option for merge-recursive: -X'diff-algorithm=patience'

> "Matwey V. Kornilov" <matwey.kornilov@gmail.com> writes:
>
>> It seems there is some issue with double escaping:
>> ...
>>> # git rebase --preserve-merges -s recursive -Xdiff-algorithm=patience
>>> --onto abc-3.8 v3.8 abc-3.9
>>>
>>> And then I see:
>>>
>>> fatal: Unknown option for merge-recursive: -X'diff-algorithm=patience'
>
> The string looks like a result of a shell script that quotes any
> end-user controlled string before incorporating into a string to be
> eval-ed, or something like that.  Is this a recent regression?  Does
> a bit older version of Git, like 2.12 or older, behave differently?
>

> Hello,
> 
> I am running git 2.15.1 and facing the following issue with linux kernel
> tree.
> 
> # git checkout v3.8
> # git branch abc-3.8
> # git checkout v3.9
> # git branch abc-3.9
> # git checkout abc-3.8
> 
> Introduce new commit on top of abc-3.8. Here, I edit README.
> 
> # vim README
> # git commit -a -v
> [abc-3.8 4bf088b5d341] Hello world
> 
> Then I try to rebase abc-3.9 on top of abc-3.8 as the following:
> 
> # git rebase --preserve-merges -s recursive -Xdiff-algorithm=patience
> --onto abc-3.8 v3.8 abc-3.9
> 
> And then I see:
> 
> fatal: Unknown option for merge-recursive: -X'diff-algorithm=patience'
> Error redoing merge e84cf5d0fd53badf3a93c790e280cc92a69ed999
> 
> Attached here is GIT_TRACE=1 output.