Re: git grep doesn't follow symbolic link

[Nguyen Thai Ngoc Duy <pclouds@gmail.com>]

On Sun, Jan 15, 2012 at 9:07 AM, Junio C Hamano <gitster@pobox.com> wrote:
> Stop and think what "git diff --follow-symlinks v1.3.0 v1.7.0" should do
> when these versions record a symbolic link, "from user perspective", if
> the link points outside the tracked contents. Naturally, the users would
> expect that the comparison is made between the contents of the file back
> when v1.3.0 was tagged and the contents of the file (which may or may not
> be the same path depending on the target of that symbolic link) back when
> v1.7.0 was tagged.
>
> But that is something that the user is *NOT* tracking with the system, and
> hence something we cannot give the right answer. Your "--follow-symlinks"
> option only encourages the *wrong* perception on the users' side, without
> supporting what it appears to promise to the users. Why could it be an
> improvement?

It's not wrong per se. It's an implication that users have to take
when they choose to use it. We may help make it clear that the
symlinks point to untracked files by putting some indication in the
diff.

When I do "git log -Sfoo -- '*.cxx'" I don't really care if bar.cxx is
a symlink. Neither does my compiler. It may be a symlink's target
change that makes "foo" appear. Git could help me detect that quickly
instead of sticking with tracked contents only.

Even if we decide --follow-symlinks=untracked is a bad idea,
--follow-symlinks=tracked (i.e. follow symlinks to tracked files only)
is still a good thing to support. And I suspect that's a more common
case as linking outside repository could is undeterministic.

The "=tracked" could be dropped if we have no other option value. I'm
thinking of --follow-symlinks=submodule, which is currently covered by
a separate option name.
-- 
Duy