From: Shreyansh Paliwal <shreyanshpaliwalcmsmn@gmail•com>
To: git@vger•kernel.org
Cc: gitster@pobox•com, ps@pks•im,
Shreyansh Paliwal <shreyanshpaliwalcmsmn@gmail•com>
Subject: [PATCH] show-index: warn when falling back to SHA-1 outside a repository
Date: Thu, 29 Jan 2026 21:06:55 +0530 [thread overview]
Message-ID: <20260129153948.224156-1-shreyanshpaliwalcmsmn@gmail.com> (raw)
In-Reply-To: <20260120140901.517928-1-shreyanshpaliwalcmsmn@gmail.com>
When 'git show-index' is run outside of a
repository and no hashing algorithm is
specified via --object-format, it silently
falls back to SHA-1, relying on the
historical default.
This works for existing SHA-1 based
index files, but the behavior can be ambiguous
and confusing when the input index file uses a
different hash algorithm, such as SHA-256.
Add a warning when this fallback happens
to make the assumption explicit and to
guide users toward using --object-format
when needed.
Additionally, wrap user-facing die() messages
with _() so they can be translated via gettext.
Signed-off-by: Shreyansh Paliwal <shreyanshpaliwalcmsmn@gmail•com>
---
builtin/show-index.c | 33 ++++++++++++++++++---------------
1 file changed, 18 insertions(+), 15 deletions(-)
diff --git a/builtin/show-index.c b/builtin/show-index.c
index 2c3e2940ce..14147c2ff2 100644
--- a/builtin/show-index.c
+++ b/builtin/show-index.c
@@ -36,39 +36,42 @@ int cmd_show_index(int argc,
if (hash_name) {
hash_algo = hash_algo_by_name(hash_name);
if (hash_algo == GIT_HASH_UNKNOWN)
- die(_("Unknown hash algorithm"));
+ die(_("unknown hash algorithm"));
repo_set_hash_algo(the_repository, hash_algo);
}
/*
* Fallback to SHA1 if we are running outside of a repository.
*
- * TODO: Figure out and implement a way to detect the hash algorithm in use by the
- * the index file passed in and use that instead.
+ * TODO: If a future implementation of index file version encodes the hash
+ * algorithm in its header, enable show-index to infer it from the
+ * header rather than relying on repository context or a default fallback.
*/
- if (!the_hash_algo)
+ if (!the_hash_algo) {
+ warning(_("assuming SHA-1; use --object-format to override"));
repo_set_hash_algo(the_repository, GIT_HASH_DEFAULT);
+ }
hashsz = the_hash_algo->rawsz;
if (fread(top_index, 2 * 4, 1, stdin) != 1)
- die("unable to read header");
+ die(_("unable to read header"));
if (top_index[0] == htonl(PACK_IDX_SIGNATURE)) {
version = ntohl(top_index[1]);
if (version < 2 || version > 2)
- die("unknown index version");
+ die(_("unknown index version"));
if (fread(top_index, 256 * 4, 1, stdin) != 1)
- die("unable to read index");
+ die(_("unable to read index"));
} else {
version = 1;
if (fread(&top_index[2], 254 * 4, 1, stdin) != 1)
- die("unable to read index");
+ die(_("unable to read index"));
}
nr = 0;
for (i = 0; i < 256; i++) {
unsigned n = ntohl(top_index[i]);
if (n < nr)
- die("corrupt index file");
+ die(_("corrupt index file"));
nr = n;
}
if (version == 1) {
@@ -76,7 +79,7 @@ int cmd_show_index(int argc,
unsigned int offset, entry[(GIT_MAX_RAWSZ + 4) / sizeof(unsigned int)];
if (fread(entry, 4 + hashsz, 1, stdin) != 1)
- die("unable to read entry %u/%u", i, nr);
+ die(_("unable to read entry %u/%u"), i, nr);
offset = ntohl(entry[0]);
printf("%u %s\n", offset, hash_to_hex((void *)(entry+1)));
}
@@ -90,15 +93,15 @@ int cmd_show_index(int argc,
ALLOC_ARRAY(entries, nr);
for (i = 0; i < nr; i++) {
if (fread(entries[i].oid.hash, hashsz, 1, stdin) != 1)
- die("unable to read sha1 %u/%u", i, nr);
+ die(_("unable to read sha1 %u/%u"), i, nr);
entries[i].oid.algo = hash_algo_by_ptr(the_hash_algo);
}
for (i = 0; i < nr; i++)
if (fread(&entries[i].crc, 4, 1, stdin) != 1)
- die("unable to read crc %u/%u", i, nr);
+ die(_("unable to read crc %u/%u"), i, nr);
for (i = 0; i < nr; i++)
if (fread(&entries[i].off, 4, 1, stdin) != 1)
- die("unable to read 32b offset %u/%u", i, nr);
+ die(_("unable to read 32b offset %u/%u"), i, nr);
for (i = 0; i < nr; i++) {
uint64_t offset;
uint32_t off = ntohl(entries[i].off);
@@ -107,9 +110,9 @@ int cmd_show_index(int argc,
} else {
uint32_t off64[2];
if ((off & 0x7fffffff) != off64_nr)
- die("inconsistent 64b offset index");
+ die(_("inconsistent 64b offset index"));
if (fread(off64, 8, 1, stdin) != 1)
- die("unable to read 64b offset %u", off64_nr);
+ die(_("unable to read 64b offset %u"), off64_nr);
offset = (((uint64_t)ntohl(off64[0])) << 32) |
ntohl(off64[1]);
off64_nr++;
--
2.52.0
next prev parent reply other threads:[~2026-01-29 15:40 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-20 14:05 [RFC][PATCH 0/3] show-index: modernize and implement auto-detection of hash algorithm Shreyansh Paliwal
2026-01-20 14:05 ` [PATCH 1/3] show-index: implement automatic hash detection Shreyansh Paliwal
2026-01-20 18:07 ` Junio C Hamano
2026-01-21 8:09 ` Patrick Steinhardt
2026-01-21 10:31 ` Shreyansh Paliwal
2026-01-23 7:22 ` Patrick Steinhardt
2026-01-23 16:08 ` Shreyansh Paliwal
2026-01-23 20:29 ` brian m. carlson
2026-01-21 10:28 ` Shreyansh Paliwal
2026-01-20 14:05 ` [PATCH 2/3] show-index: use gettext wrapping in error messages Shreyansh Paliwal
2026-01-20 14:05 ` [PATCH 3/3] show-index: remove global state variables Shreyansh Paliwal
2026-01-21 10:39 ` Phillip Wood
2026-01-21 12:47 ` Shreyansh Paliwal
2026-01-21 17:23 ` Junio C Hamano
2026-01-29 15:36 ` Shreyansh Paliwal [this message]
2026-01-29 23:03 ` [PATCH] show-index: warn when falling back to SHA-1 outside a repository Junio C Hamano
2026-01-30 8:59 ` Shreyansh Paliwal
2026-01-29 23:12 ` brian m. carlson
2026-01-30 9:04 ` Shreyansh Paliwal
2026-01-30 13:40 ` Patrick Steinhardt
2026-01-30 17:01 ` Junio C Hamano
2026-01-30 15:31 ` [PATCH V2 0/2] show-index: add warning and wrap error messages with gettext Shreyansh Paliwal
2026-01-30 15:31 ` [PATCH V2 1/2] show-index: warn when falling back to SHA-1 outside a repository Shreyansh Paliwal
2026-01-30 15:31 ` [PATCH V2 2/2] show-index: use gettext wrapping in user facing error messages Shreyansh Paliwal
2026-01-30 17:07 ` [PATCH V2 0/2] show-index: add warning and wrap error messages with gettext Junio C Hamano
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