Re: [PATCH] filter-branch: assume HEAD if no revision supplied

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 30, 2008, 21:03 UTC
Message-ID: <7vk5lrgh56.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <alpine.LSU.1.00.0801302034310.23907@racer.site>

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

Show 9 quoted lines

> On Wed, 30 Jan 2008, Brandon Casey wrote:
>
>> filter-branch previously took the first non-option argument as the name 
>> for a new branch. Since dfd05e38, it now takes a revision or a revision 
>> range and modifies the current branch. Update to operate on HEAD by 
>> default to conform with standard git interface practice.
>
> FWIW I think the code wanted to let "git filter-branch" without options 
> print the usage.

That might be a valid safety concern to some folks. Previously we have seen people say "Whenever I see a command foo that I do not know what it does, I type 'foo <Enter>' and expect it gives the usage back. So any new destructive command 'foo' should not do a damage by using built-in default." (I think it was about "git stash" without parameter).

By the way, I do not personally think it is worth to be heavily supportive to the practice of trying an unknown command without understanding, and I do not agree such a safety is necessarily a good idea, especially if it makes normal use of the command more cumbersome by people who understand what it does.

Even though "git stash" itself is not destrictive, you need to know its "apply" subcommand to undo the action. In that sense, it is destructive to clueless people who blindly type whatever command they see.

That's why we still allow you to say "git stash", but we removed its "git stash <randam message>" syntax, which was risky when subcommand name was misspelled even by people who know what the command does. I think we struck a good balance between usability and safety there. And I think we can do the same here.

Perhaps "git filter-branch <Enter>" can be prevented as in the current implementation while "git filter-branch --foo-filter foo" can default to HEAD to satisfy both needs. The command without any filter is supposed to be mostly no-op (unless you are trying to rewrite the history with grafts).