If a candidate HEAD isn't a symref, we check that it
contains a viable sha1. But in a post-sha1 world, we should
be checking whether it has any plausible object-id.
We can do that by switching to get_oid_hex().
Note that both before and after this patch, we only check
for a plausible object id at the start of the file, and then
call that good enough. We ignore any content _after_ the
hex, so a string like:
0123456789012345678901234567890123456789 foo
is accepted. Though we do put extra bytes like this into
some pseudorefs (e.g., FETCH_HEAD), we don't typically do so
with HEAD. We could tighten this up by using parse_oid_hex(),
like:
if (!parse_oid_hex(buffer, &oid, &end) &&
*end++ == '\n' && *end == '\0')
return 0;
But we're probably better to remain on the loose side. We're
just checking here for a plausible-looking repository
directory, so heuristics are acceptable (if we really want
to be meticulous, we should use the actual ref code to parse
HEAD).
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
path.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/path.c b/path.c
index 2ef3a86613..5aa9244eb2 100644
--- a/path.c
+++ b/path.c
@@ -639,7 +639,7 @@ int validate_headref(const char *path)
struct stat st;
char buffer[256];
const char *refname;
- unsigned char sha1[20];
+ struct object_id oid;
int fd;
ssize_t len;
@@ -680,7 +680,7 @@ int validate_headref(const char *path)
/*
* Is this a detached HEAD?
*/
- if (!get_sha1_hex(buffer, sha1))
+ if (!get_oid_hex(buffer, &oid))
return 0;
return -1;
--
2.14.2.988.g01c8b37dde
