Re: [PATCH v3] describe: refresh the index when 'broken' flag is used

> Junio C Hamano <gitster@pobox.com> writes:
>
>> (#leftoverbit)
>>
>> Outside the scope of this patch, I'd prefer to see somebody makes
>> sure that it is truly equivalent to prepare a separate and new
>> struct child_process for each run_command() call and to reuse the
>> same struct child_process after calling child_process_clear() each
>> time.  It is unclear if they are equivalent in general, even though
>> in this particular case I think we should be OK.
>>
>> There _might_ be other things in the child_process structure that
>> need to be reset to the initial state before it can be reused, but
>> are not cleared by child_process_clear().  .git_cmd and other flags
>> as well as in/out/err file descriptors do not seem to be cleared,
>> and other callers of run_command() may even be depending on the
>> current behaviour that they are kept.
>
> Ahh, the reuse of the same struct came directly from Karthik's
> review on the second iteration.  I guess Karthik volunteered himself
> into this #leftoverbit task?  I am not convinced that
>

>  (1) the selective clearing done by current child_process_clear() is
>      the best thing we can do to make child_process reusable, and
>
>  (2) among the current callers, there is nobody that depends on the
>      state left by the previous use of child_process in another
>      run_command() call that is left uncleared by child_process_clear().
>
> If (1) is false, then reusing child_process structure is not quite
> safe, and if (2) is false, updating child_process_clear() to really
> clear everything will first need to adjust some callers.
>
> Thanks.
>