Re: [PATCH v2 3/4] show-ref: Optimize show_ref a bit

Junio C Hamano [off-list ref] writes:

Having to do this change probably is an indication that the division
of labour between show_ref() and show_one() up to this step needs to
be rethought.

Conceptually, "git show-ref" works in two ways:

 * When in --verify mode, the end user gives which refnames to
   consider showing.

 * Otherwise the end user gives pattern and the command infers which
   refnames to consider showing using the pattern.

And for the refnames that are considered for showing, we may do
various things, like -d to deref and --quiet to be silent.  We want
this actual "output" step to be the same between two modes of
operation.

... also "error out if the named object did not exist" can be part
of this, which means ...

So a better division of labour would be:

 * Make show_ref() about "using pattern, enumerate what refs to
   show" and call show_one().

 * Update show_one() and teach _it_ to handle quiet and deref_tags.

... "if (!has_sha1_file(oid->hash)) die()" in show_ref() would
probably want to be part of this update.