[PATCH v6 0/6] object-name: make ambiguous object output translatable + show tag date

This topic improves the output we emit on ambiguous objects as noted in 4/6, and makes it translatable, see 3/6. See [1] for v5.

This iteration addresses various small feedback from Josh Steadmon. I've incorporated a variable rename fixups here, and hopefully answered small questions on the v5 thread with amended commit messages.

For the case of "dead" prefixed objects being unused but "beef" being used I just added a test for the "dead" objects. They're not strictly needed, but having them for the "dead...beef" symetry and for use in future tests is probably better, so I kept them in.

1. http://lore.kernel.org/git/cover-v5-0.6-00000000000-20211125T215529Z-avarab@gmail.com

Ævar Arnfjörð Bjarmason (6):
  object-name tests: add tests for ambiguous object blind spots
  object-name: explicitly handle OBJ_BAD in show_ambiguous_object()
  object-name: make ambiguous object output translatable
  object-name: show date for ambiguous tag objects
  object-name: iterate ambiguous objects before showing header
  object-name: re-use "struct strbuf" in show_ambiguous_object()

 object-name.c                       | 112 +++++++++++++++++++++++++---
 t/t1512-rev-parse-disambiguation.sh |  84 +++++++++++++++++++++
 2 files changed, 184 insertions(+), 12 deletions(-)

Range-diff against v5:
1:  767165d096d ! 1:  27f267ad555 object-name tests: add tests for ambiguous object blind spots
    @@ Commit message
         prefix are the same for both SHA-1 and SHA-256. This uses strings that
         I mined, and have the same prefix when hashed with both.
     
    +    We "test_cmp" the full output to guard against any future regressions,
    +    and because a subsequent commit will tweak it. Showing a diff of how
    +    the output changes is helpful to explain those subsequent commits.
    +
         1. https://lore.kernel.org/git/YZwbphPpfGk78w2f@coredump.intra.peff.net/
     
         Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
    @@ t/t1512-rev-parse-disambiguation.sh: export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
     +		echo 1bbfctrkc | git hash-object -w --stdin
     +	) &&
     +
    ++	test_must_fail git -C blob.prefix rev-parse dead &&
     +	cat >expect <<-\EOF &&
     +	error: short object ID beef... is ambiguous
     +	hint: The candidates are:
2:  ee86912f1c1 ! 2:  c78243dc701 object-name: explicitly handle OBJ_BAD in show_ambiguous_object()
    @@ Commit message
         added in the preceding commit.
     
         So saying "unknown type" here was always misleading, we really meant
    -    to say that we had a failure parsing the object at all, if the problem
    -    is only that it's type is unknown we won't reach this code.
    +    to say that we had a failure parsing the object at all, i.e. that we
    +    had repository corruption. If the problem is only that it's type is
    +    unknown we won't reach this code.
     
         So let's emit a generic "[bad object]" instead. As our tests added in
         the preceding commit show, we'll have emitted various "error" output
3:  b79964483e8 ! 3:  daebc95542c object-name: make ambiguous object output translatable
    @@ Commit message
            then SHA-1, 2018-05-10)
     
         Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
    +    Signed-off-by: Josh Steadmon <steadmon@google.com>
     
      ## object-name.c ##
     @@ object-name.c: static int show_ambiguous_object(const struct object_id *oid, void *data)
    @@ object-name.c: static int show_ambiguous_object(const struct object_id *oid, voi
     -	strbuf_addstr(&desc, type_name(type));
      
      	if (type == OBJ_COMMIT) {
    -+		struct strbuf ad = STRBUF_INIT;
    -+		struct strbuf s = STRBUF_INIT;
    ++		struct strbuf date = STRBUF_INIT;
    ++		struct strbuf msg = STRBUF_INIT;
      		struct commit *commit = lookup_commit(ds->repo, oid);
     +
      		if (commit) {
      			struct pretty_print_context pp = {0};
      			pp.date_mode.type = DATE_SHORT;
     -			format_commit_message(commit, " %ad - %s", &desc, &pp);
    -+			format_commit_message(commit, "%ad", &ad, &pp);
    -+			format_commit_message(commit, "%s", &s, &pp);
    ++			format_commit_message(commit, "%ad", &date, &pp);
    ++			format_commit_message(commit, "%s", &msg, &pp);
      		}
     +
     +		/*
    @@ object-name.c: static int show_ambiguous_object(const struct object_id *oid, voi
     +		 *
     +		 *    "deadbeef commit 2021-01-01 - Some Commit Message"
     +		 */
    -+		strbuf_addf(&desc, _("%s commit %s - %s"), hash, ad.buf, s.buf);
    ++		strbuf_addf(&desc, _("%s commit %s - %s"),
    ++			    hash, date.buf, msg.buf);
     +
    -+		strbuf_release(&ad);
    -+		strbuf_release(&s);
    ++		strbuf_release(&date);
    ++		strbuf_release(&msg);
      	} else if (type == OBJ_TAG) {
      		struct tag *tag = lookup_tag(ds->repo, oid);
     +		const char *tag_tag = "";
4:  36b6b440c37 = 4:  b5aa6e266f6 object-name: show date for ambiguous tag objects
5:  8880c283559 = 5:  644b076b2a6 object-name: iterate ambiguous objects before showing header
6:  78bb0995f08 ! 6:  6a31cfcfc29 object-name: re-use "struct strbuf" in show_ambiguous_object()
    @@ object-name.c: static int show_ambiguous_object(const struct object_id *oid, voi
      		 *
      		 *    "deadbeef commit 2021-01-01 - Some Commit Message"
      		 */
    --		strbuf_addf(&desc, _("%s commit %s - %s"), hash, ad.buf, s.buf);
    -+		strbuf_addf(sb, _("%s commit %s - %s"), hash, ad.buf, s.buf);
    +-		strbuf_addf(&desc, _("%s commit %s - %s"),
    +-			    hash, date.buf, msg.buf);
    ++		strbuf_addf(sb, _("%s commit %s - %s"), hash, date.buf,
    ++			    msg.buf);
      
    - 		strbuf_release(&ad);
    - 		strbuf_release(&s);
    + 		strbuf_release(&date);
    + 		strbuf_release(&msg);
     @@ object-name.c: static int show_ambiguous_object(const struct object_id *oid, void *data)
      		 * object.c, it should (hopefully) already be
      		 * translated.