patchgc --auto: do not run 'pack-refs' and 'reflog expire' twice

>
> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
> ---
>  builtin/gc.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/builtin/gc.c b/builtin/gc.c
> index 8d219d8..fb0cff3 100644
> --- a/builtin/gc.c
> +++ b/builtin/gc.c
> @@ -261,6 +261,11 @@ static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
>  
>  static int gc_before_repack(void)
>  {
> +	static int nr_runs;
> +
> +	if (nr_runs++)
> +		return 0;
> +
>  	if (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD))
>  		return error(FAILED_RUN, pack_refs_cmd.argv[0]);

> Nguyễn Thái Ngọc Duy  <pclouds@gmail.com> writes:
>
>> In the --auto code path, gc_before_repack() is called once in parent
>> process then again in the forked process. Stop the second run.
>
> Hmph.  Is the true reason why this happens because we have two calls
> to gc_before_repack() in the main, and one is before daemonize()?
> Shouldn't this protection be in the caller?

>> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
>> ---
>>  builtin/gc.c | 5 +++++
>>  1 file changed, 5 insertions(+)
>>
>> diff --git a/builtin/gc.c b/builtin/gc.c
>> index 8d219d8..fb0cff3 100644
>> --- a/builtin/gc.c
>> +++ b/builtin/gc.c
>> @@ -261,6 +261,11 @@ static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
>>  
>>  static int gc_before_repack(void)
>>  {
>> +	static int nr_runs;
>> +
>> +	if (nr_runs++)
>> +		return 0;
>> +
>>  	if (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD))
>>  		return error(FAILED_RUN, pack_refs_cmd.argv[0]);

> Junio C Hamano <gitster@pobox.com> writes:
>
>> Nguyễn Thái Ngọc Duy  <pclouds@gmail.com> writes:
>>
>>> In the --auto code path, gc_before_repack() is called once in parent
>>> process then again in the forked process. Stop the second run.
>>
>> Hmph.  Is the true reason why this happens because we have two calls
>> to gc_before_repack() in the main, and one is before daemonize()?
>> Shouldn't this protection be in the caller?
>
> Actually, I think the function already is protecting wastage of
> getting called twice by saying "I've done pack-refs already" and
> "I've done prune-reflogs already" by setting the two variables to
> zero.  Isn't that sufficient?
>
> What problem is this patch trying to fix?