Re: [PATCH v2 2/4] git-p4: create new method gitRunHook

Ben Keene [off-list ref] writes:

On 2/5/2020 4:42 PM, Junio C Hamano wrote:

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Ben Keene [off-list ref] writes:

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+        hooks_path = os.path.join(os.environ.get("GIT_DIR", ".git"), "hooks")

This assumes that the process when his function is called (by the
way, even though the title of the patch uses the word "method", this
is not a method but a function, no?), it is always at the top level
of the working tree.  Is that a good assumption?  I don't know the
code well, so "yes it is good because a very early thing we do is to
go up to the top" is a good answer.

...

As best as I understand the mechanics, and I haven't examined the
source code of git, this is just experimental,...

As I already said that I do not know the code well, it is useless
for you to also speculate.  One of us must read the code before
speaking further ;-)

I just scanned "def main()", and it seems that it always goes to the
top-level of the working tree by doing chdir(cdup), where cdup is
learned from "git rev-parse --show-cdup", i.e. "tell me how to chdir
up to the top-level of the working tree".

I am assuming that nobody runs "git p4" in a bare repository, so
under that assumption, I think it would be safe to say that we can
assume we are always at the top.  Also, GIT_DIR is exported from
there, so it probably is a good idea to make sure that the run-hook
helper just uses os.environ.get("GIT_DIR") and barfs if the environ
is not set (i.e. there is something funny going on) without
pretending that it is prepared to deal with such a case, which is
what the "[, default]" parameter to .get method is doing.

I.e.

	hooks_path = os.path.join(os.environ["GIT_DIR"], "hooks")
    

Does this prompt the need to search the hierarchy if we don't find
the directory?

No, we just saw that it is done early in "def main()".  It is done
by "rev-parse --git-dir" and "rev-parse --show-cdup".