Subject: Re: Segfault: git show-branch --reflog refs/pullreqs/1

From: Junio C Hamano <[email-masked]>
Date: Wed, 21 Feb 2024 09:44:09 -0800

Jeff King <[email-masked]> writes:

> with an empty reflog file (added by that same commit). The code in
> get_oid_basic() to parse reflogs doesn't suffer from the same bugs: it
> checks up front that the reflog file exists, it preloads the output oid
> with the current ref value, and it doesn't look at other fields (like
> the reflog message).

It is a usability hack to allow foo@{0} to resolve successfully,
instead of causing a failure, when there is no reflog entries for
foo, I would think.  As to the "show-branch -g", the intent is to
see the recent evolution of the branch, so I am fine if we do not
give any output when no reflog entries exist (i.e. "no evolution
behind the current state---it just is"), or just one entry output
for "foo@{0}" to say "there is only one recent state".

Even though it may feel wrong to successfully resolve foo@{0} when
reflog for foo does not exist at the mechanical level (read: the
implementors of reflog mechanism may find the usability hack a bad
idea), I suspect at the end-user level it may be closer to what
people expect out of foo@{0} (i.e. "give me the latest").

Thanks.