Re: [PATCH] Documentation/githooks: Explain pre-rebase parameters
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Feb 19, 2013, 19:08 UTC
- Message-ID
- <7vk3q45dg2.fsf@alter.siamese.dyndns.org>
- In-Reply-To
- <c19c03f51d71a58fa3795f665fe4a4c0461fa58f.1361271116.git.wking@tremily.us>
"W. Trevor King" <wking@tremily.us> writes:
Show 23 quoted lines
> From: "W. Trevor King" <wking@tremily.us>
>
> Descriptions borrowed from templates/hooks--pre-rebase.sample.
>
> Signed-off-by: W. Trevor King <wking@tremily.us>
> ---
> I'm not 100% convinced about this, because the git-rebase.sh uses:
>
> "$GIT_DIR/hooks/pre-rebase" ${1+"$@"}
>
> I haven't been able to find documentation for the ${1+"$@"} syntax.
> Is it in POSIX? It's not in the Bash manual:
>
> $ man bash | grep '\${.*[+]'
> (${BASH_SOURCE[$i+1]}) where ${FUNCNAME[$i]} was called (or
> ${BASH_SOURCE[$i+1]}.
> ${BASH_SOURCE[$i+1]} at line number ${BASH_LINENO[$i]}. The
> ${parameter:+word}
>
> In my local tests, it seems equivalent to "$@".
>
> Also, it appears that the `git-rebase--*.sh` handlers don't use the
> pre-rebase hook. Is this intentional?The codeflow of git-rebase front-end, when you start rebasing, will call run_pre_rebase_hook before calling run_specific_rebase. It will be redundant for handlers to then call it again, no?
In "rebase --continue" and later steps, you would not want to see the hook trigger.
Show 18 quoted lines
> Documentation/githooks.txt | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/Documentation/githooks.txt b/Documentation/githooks.txt > index b9003fe..bc837c6 100644 > --- a/Documentation/githooks.txt > +++ b/Documentation/githooks.txt > @@ -140,9 +140,10 @@ the outcome of 'git commit'. > pre-rebase > ~~~~~~~~~~ > > -This hook is called by 'git rebase' and can be used to prevent a branch > -from getting rebased. > - > +This hook is called by 'git rebase' and can be used to prevent a > +branch from getting rebased. The hook takes two parameters: the > +upstream the series was forked from and the branch being rebased. The > +second parameter will be empty when rebasing the current branch.
Technically this is incorrect.
We call it with one or two parameters, and sometimes the second parameter is _missing_, which is different from calling with an empty string. For a script written in some scripting languages like shell and perl, the distinction may not matter (i.e. $2 and $ARGV[1] will be an empty string when stringified) but not all (accessing sys.argv[2] may give you an IndexError in Python).