Re: [PATCH v2 2/2] githooks.txt: Clarify documentation on reference-transaction hook

[Junio C Hamano <gitster@pobox.com>]

Patrick Steinhardt <ps@pks.im> writes:

> The reference-transaction hook doesn't clearly document its scope and
> what values it receives as input. Document it to make it less surprising
> and clearly delimit its (current) scope.

Sounds good (especially "that may change in the future" part is a
nice touch).

Thanks.

> Signed-off-by: Patrick Steinhardt <ps@pks.im>
> ---
>  Documentation/githooks.txt | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/githooks.txt b/Documentation/githooks.txt
> index 4dad80052e..b51959ff94 100644
> --- a/Documentation/githooks.txt
> +++ b/Documentation/githooks.txt
> @@ -473,7 +473,8 @@ reference-transaction
>  
>  This hook is invoked by any Git command that performs reference
>  updates. It executes whenever a reference transaction is prepared,
> -committed or aborted and may thus get called multiple times.
> +committed or aborted and may thus get called multiple times. The hook
> +does not cover symbolic references (but that may change in the future).
>  
>  The hook takes exactly one argument, which is the current state the
>  given reference transaction is in:
> @@ -492,6 +493,14 @@ receives on standard input a line of the format:
>  
>    <old-value> SP <new-value> SP <ref-name> LF
>  
> +where `<old-value>` is the old object name passed into the reference
> +transaction, `<new-value>` is the new object name to be stored in the
> +ref and `<ref-name>` is the full name of the ref. When force updating
> +the reference regardless of its current value or when the reference is
> +to be created anew, `<old-value>` is the all-zeroes object name. To
> +distinguish these cases, you can inspect the current value of
> +`<ref-name>` via `git rev-parse`.
> +
>  The exit status of the hook is ignored for any state except for the
>  "prepared" state. In the "prepared" state, a non-zero exit status will
>  cause the transaction to be aborted. The hook will not be called with