[02/30] oid-array: Teach oid-array to handle multiple kinds of oids

Commit Message

Eric W. Biederman Sept. 27, 2023, 7:55 p.m. UTC

From: "Eric W. Biederman" <[e-mail]>

While looking at how to handle input of both SHA-1 and SHA-256 oids in
get_oid_with_context, I realized that the oid_array in
repo_for_each_abbrev might have more than one kind of oid stored in it
simulataneously.

Update to oid_array_append to ensure that oids added to an oid array
always have an algorithm set.

Update void_hashcmp to first verify two oids use the same hash algorithm
before comparing them to each other.

With that oid-array should be safe to use with differnt kinds of
oids simultaneously.

Signed-off-by: "Eric W. Biederman" <[e-mail]>
---
 oid-array.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

Comments

Eric Sunshine Sept. 27, 2023, 11:20 p.m. UTC | #1

On Wed, Sep 27, 2023 at 3:55 PM Eric W. Biederman <[e-mail]> wrote:
> While looking at how to handle input of both SHA-1 and SHA-256 oids in
> get_oid_with_context, I realized that the oid_array in
> repo_for_each_abbrev might have more than one kind of oid stored in it
> simulataneously.

s/simulataneously/simultaneously/

> Update to oid_array_append to ensure that oids added to an oid array
> always have an algorithm set.
>
> Update void_hashcmp to first verify two oids use the same hash algorithm
> before comparing them to each other.
>
> With that oid-array should be safe to use with differnt kinds of
> oids simultaneously.

s/differnt/different/

> Signed-off-by: "Eric W. Biederman" <[e-mail]>

Patch

diff --git a/oid-array.c b/oid-array.c
index 8e4717746c31..1f36651754ed 100644
--- a/oid-array.c
+++ b/oid-array.c
@@ -6,12 +6,20 @@  void oid_array_append(struct oid_array *array, const struct object_id *oid)
 {
 	ALLOC_GROW(array->oid, array->nr + 1, array->alloc);
 	oidcpy(&array->oid[array->nr++], oid);
+	if (!oid->algo)
+		oid_set_algo(&array->oid[array->nr - 1], the_hash_algo);
 	array->sorted = 0;
 }
 
-static int void_hashcmp(const void *a, const void *b)
+static int void_hashcmp(const void *va, const void *vb)
 {
-	return oidcmp(a, b);
+	const struct object_id *a = va, *b = vb;
+	int ret;
+	if (a->algo == b->algo)
+		ret = oidcmp(a, b);
+	else
+		ret = a->algo > b->algo ? 1 : -1;
+	return ret;
 }
 
 void oid_array_sort(struct oid_array *array)