Re: [PATCH 1/2] ref-filter: hacky "streaming" mode
From: Jeff King <hidden>
Date: 2021-09-10 14:26:34
On Thu, Sep 09, 2021 at 10:45:15PM +0800, ZheNing Hu wrote:
quoted hunk ↗ jump to hunk
@@ -2735,6 +2723,7 @@ void pretty_print_ref(const char *name, conststruct object_id *oid, ref_item = new_ref_array_item(name, oid); ref_item->kind = ref_kind_from_refname(name); + read_ref_full(name, 0, NULL, &ref_item->flag); if (format_ref_array_item(ref_item, format, &output, &err)) die("%s", err.buf); fwrite(output.buf, 1, output.len, stdout);
IMHO this is the wrong place to do it, since the caller may already have the flags (and looking up the ref again is a non-trivial cost). The caller in builtin/tag.c should switch to using read_ref_full() and pass in the flags. The caller in builtin/verify-tag.c _probably_ should resolve the ref in the same way and pass in that full refname and flags. I do worry that this may be a compatibility problem, but the current behavior seems so broken to me.
quoted
- I suspect people may be relying on the current behavior. The original was added to be able to compare the internal tagname to the refname. I.e., that: git tag -v --format='%(refname) %(tag)' foo would show "foo foo". Now that _should_ be "%(refname:strip=2)", I think, but we'd probably be breaking scripts. OTOH, it really feels like _not_ handing over a real, fully-qualified refname to the ref-filter code will mean other things are broken (e.g., ATOM_UPSTREAM is assuming we have a fully-qualified ref).This is indeed a sad thing: A bug becomes a feature.quoted
I think a backwards-compatible way of fixing it would be to have this call hand over the full refname to the ref-filter code, but tell it that %(refname) should default to strip=2. And then anybody who wants the full name can use %(refname:strip=0).Doesn't this make things more complicated? Those callers of git for-each-ref, wouldn't our changes like this destroy them?
My proposal was that we'd have a specific flag in ref-filter to say "default refname:strip to this value". And then _only_ "tag --verify" would set that (to "2"), leaving for-each-ref, etc unaffected. So yes, it's complicated. And it must be explained to the user that "%(refname)" behaves slightly differently with "git tag --verify", but that is unavoidable if we do not want to break scripts (it _already_ behaves slightly differently, and we just never told anyone). The other option is to declare the current behavior a bug and fix it. I am quite tempted by that route, given the inconsistency with other formatters, including even "git tag --list --format=%(refname)"! -Peff