Re: [PATCH 3/1] update-index doc: note a fixed bug in the untracked cache

> Document the bug tested for in my "status: add a failing test showing
> a core.untrackedCache bug" and fixed in Duy's "dir.c: fix missing dir
> invalidation in untracked code".
>
> Since this is very likely something others will encounter in the
> future on older versions, and it's not obvious how to fix it let's
> document both that it exists, and how to "fix" it with a one-off
> command.
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---
>
>> On Tue, Dec 26, 2017 at 05:47:19PM +0700, Duy Nguyen wrote:
>>> Strangely, root dir is not cached (no valid flag). I don't know why
>>> but that's ok we'll roll with it.
>>
>> I figured this out. Which is good because now I know how/why the bug
>> happens.
>
> Thanks a lot. I think it's probably good to apply something like this
> on top of this now 3-patch series.

>
>  Documentation/git-update-index.txt | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/Documentation/git-update-index.txt b/Documentation/git-update-index.txt
> index bdb0342593..bc6c32002f 100644
> --- a/Documentation/git-update-index.txt
> +++ b/Documentation/git-update-index.txt
> @@ -464,6 +464,17 @@ command reads the index; while when `--[no-|force-]untracked-cache`
>  are used, the untracked cache is immediately added to or removed from
>  the index.
>  
> +Before 2.16, the untracked cache had a bug where replacing a directory
> +with a symlink to another directory could cause it to incorrectly show
> +files tracked by git as untracked. See the "status: add a failing test
> +showing a core.untrackedCache bug" commit to git.git. A workaround for
> +that was (and this might work for other undiscoverd bugs in the
> +future):
> +
> +----------------
> +$ git -c core.untrackedCache=false status
> +----------------
> +
>  File System Monitor
>  -------------------