[PATCH v4 06/10] refs: root refs can be symbolic refs
- From
Patrick Steinhardt <ps@pks.im>
- Date
- May 10, 2024, 08:48 UTC
- Message-ID
- <5e402811a668ae7659175c6f91da6bbb982bacf1.1715330206.git.ps@pks.im>
- In-Reply-To
- <cover.1715330206.git.ps@pks.im>
Before this patch series, root refs except for "HEAD" and our special refs were classified as pseudorefs. Furthermore, our terminology clarified that pseudorefs must not be symbolic refs. This restriction is enforced in `is_root_ref()`, which explicitly checks that a supposed root ref resolves to an object ID without recursing.
This has been extremely confusing right from the start because (in old terminology) a ref name may sometimes be a pseudoref and sometimes not depending on whether it is a symbolic or regular ref. This behaviour does not seem reasonable at all and I very much doubt that it results in anything sane.
Last but not least, the current behaviour can actually lead to a segfault when calling `is_root_ref()` with a reference that either does not exist or that is a symbolic ref because we never initialized `oid`.
Let's loosen the restrictions in accordance to the new definition of root refs, which are simply plain refs that may as well be a symbolic ref. Consequently, we can just check for the ref to exist instead of requiring it to be a regular ref.
Add a test that verifies that this does not change user-visible behaviour. Namely, we still don't want to show broken refs to the user by default in git-for-each-ref(1). What this does allow though is for internal callers to surface dangling root refs when they pass in the `DO_FOR_EACH_INCLUDE_BROKEN` flag.
Signed-off-by: Patrick Steinhardt <ps@pks.im> --- refs.c | 31 ++++++++++++++++++++----------- refs.h | 3 ++- t/t6302-for-each-ref-filter.sh | 17 +++++++++++++++++ 3 files changed, 39 insertions(+), 12 deletions(-)
diff --git a/refs.c b/refs.c index 6266f77474..d63d60a0dc 100644 --- a/refs.c +++ b/refs.c @@ -869,28 +869,37 @@ int is_root_ref(struct ref_store *refs, const char *refname) "NOTES_MERGE_REF", "MERGE_AUTOSTASH", }; - struct object_id oid; + struct strbuf referent = STRBUF_INIT; + struct object_id oid = { 0 }; + int failure_errno, ret = 0; + unsigned int flags; size_t i; if (!is_root_ref_syntax(refname)) return 0; + /* + * Note that we cannot use `refs_ref_exists()` here because that also + * checks whether its target ref exists in case refname is a symbolic + * ref. + */ if (ends_with(refname, "_HEAD")) { - refs_resolve_ref_unsafe(refs, refname, - RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE, - &oid, NULL); - return !is_null_oid(&oid); + ret = !refs_read_raw_ref(refs, refname, &oid, &referent, + &flags, &failure_errno); + goto done; } - for (i = 0; i < ARRAY_SIZE(irregular_root_refs); i++) + for (i = 0; i < ARRAY_SIZE(irregular_root_refs); i++) { if (!strcmp(refname, irregular_root_refs[i])) { - refs_resolve_ref_unsafe(refs, refname, - RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE, - &oid, NULL); - return !is_null_oid(&oid); + ret = !refs_read_raw_ref(refs, refname, &oid, &referent, + &flags, &failure_errno); + goto done; } + } - return 0; +done: + strbuf_release(&referent); + return ret; } int is_headref(struct ref_store *refs, const char *refname) diff --git a/refs.h b/refs.h index d0374c3275..b15ac3835e 100644 --- a/refs.h +++ b/refs.h @@ -1052,7 +1052,8 @@ extern struct ref_namespace_info ref_namespace[NAMESPACE__COUNT]; void update_ref_namespace(enum ref_namespace namespace, char *ref); /* - * Check whether the reference is an existing root reference. + * Check whether the reference is an existing root reference. A root reference + * that is a dangling symbolic ref is considered to exist. * * A root ref is a reference that lives in the root of the reference hierarchy. * These references must conform to special syntax: diff --git a/t/t6302-for-each-ref-filter.sh b/t/t6302-for-each-ref-filter.sh index 948f1bb5f4..92ed8957c8 100755 --- a/t/t6302-for-each-ref-filter.sh +++ b/t/t6302-for-each-ref-filter.sh @@ -62,6 +62,23 @@ test_expect_success '--include-root-refs with other patterns' ' test_cmp expect actual ' +test_expect_success '--include-root-refs omits dangling symrefs' ' + test_when_finished "rm -rf repo" && + git init repo && + ( + cd repo && + test_commit initial && + git symbolic-ref DANGLING_HEAD refs/heads/missing && + cat >expect <<-EOF && + HEAD + $(git symbolic-ref HEAD) + refs/tags/initial + EOF + git for-each-ref --format="%(refname)" --include-root-refs >actual && + test_cmp expect actual + ) +' + test_expect_success 'filtering with --points-at' ' cat >expect <<-\EOF && refs/heads/main
-- 2.45.0