regarding fix on "git clone $there $here"

> Recently we try to upgrade ubuntu from 17.10 to 18.04, then we found
> one inconsistent behavior on git clone.
> 
> At 2.14.1 or 2.15.1, if I run command like 
>  - mkdir /tmp/111
>  - git clone git@github.com:111/111 /tmp/111
> 
> because it will failure, then /tmp/111 will be removed automatically.
> 
> However, at latest 2.17.0 which is part of ubuntu 18.04, seems like
> git clone failure will not auto remove this folder. I notice 2.16.2
> and 2.17.0 release note includes this fix. So just wonder to know if
> prior behavior was think of bug, and this fix has change the behavior. 
> 
>  * "git clone $there $here" is allowed even when here directory exists
>    as long as it is an empty directory, but the command incorrectly
>    removed it upon a failure of the operation.

> At 2.14.1 or 2.15.1, if I run command like 
>  - mkdir /tmp/111
>  - git clone git@github.com:111/111 /tmp/111
>
> because it will failure, then /tmp/111 will be removed automatically.

> On May 8, 2018, at 11:44 PM, Junio C Hamano <gitster@pobox.com> wrote:
> 
> Leslie Wang <qiwa@pensando.io> writes:
> 
>> At 2.14.1 or 2.15.1, if I run command like 
>> - mkdir /tmp/111
>> - git clone git@github.com:111/111 /tmp/111
>> 
>> because it will failure, then /tmp/111 will be removed automatically.
> 
> Yes, this was a (longstanding) bug that nobody bothered to fix for a
> long time.  As "git clone" did not create /tmp/111 but it was given
> to it by the external world, it shouldn't remove it upon failure.
> Of course, if you omit the "mkdir" in the above sequence and let
> "git clone" create /tmp/111, tne Git will remove it upon failure as
> part of the clean-up.
>