[PATCH v2 02/16] object-name: allow skipping ambiguity checks in `get_oid()` family

[Patrick Steinhardt <ps@pks.im>]

When reading an object ID via `get_oid_basic()` or any of its related
functions we perform a check whether the object ID is ambiguous, which
can be the case when a reference with the same name exists. While the
check is generally helpful, there are cases where it only adds to the
runtime overhead without providing much of a benefit.

Add a new flag that allows us to disable the check. The flag will be
used in a subsequent commit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 hash.h        | 1 +
 object-name.c | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/hash.h b/hash.h
index 4367acfec50..79419016513 100644
--- a/hash.h
+++ b/hash.h
@@ -204,6 +204,7 @@ struct object_id {
 #define GET_OID_ONLY_TO_DIE    04000
 #define GET_OID_REQUIRE_PATH  010000
 #define GET_OID_HASH_ANY      020000
+#define GET_OID_SKIP_AMBIGUITY_CHECK 040000
 
 #define GET_OID_DISAMBIGUATORS \
 	(GET_OID_COMMIT | GET_OID_COMMITTISH | \
diff --git a/object-name.c b/object-name.c
index bc0265ad2a1..3e0b7edea11 100644
--- a/object-name.c
+++ b/object-name.c
@@ -961,7 +961,9 @@ static int get_oid_basic(struct repository *r, const char *str, int len,
 	int fatal = !(flags & GET_OID_QUIETLY);
 
 	if (len == r->hash_algo->hexsz && !get_oid_hex(str, oid)) {
-		if (repo_settings_get_warn_ambiguous_refs(r) && warn_on_object_refname_ambiguity) {
+		if (!(flags & GET_OID_SKIP_AMBIGUITY_CHECK) &&
+		    repo_settings_get_warn_ambiguous_refs(r) &&
+		    warn_on_object_refname_ambiguity) {
 			refs_found = repo_dwim_ref(r, str, len, &tmp_oid, &real_ref, 0);
 			if (refs_found > 0) {
 				warning(warn_msg, len, str);

-- 
2.48.1.683.gf705b3209c.dirty