get_sha1_with_context: dynamically allocate oc->path

When a sha1 lookup returns the tree path via "struct
object_context", it just copies it into a fixed-size buffer.
This means the result can be truncated, and it means our
"struct object_context" consumes a lot of stack space.

Instead, let's allocate a string on the heap. Because most
callers don't care about this information, we'll avoid doing
it by default (so they don't all have to start calling
free() on the result). There are basically two options for
the caller to signal to us that it's interested:

  1. By setting a pointer to storage in the object_context.

  2. By passing a flag in another parameter.

Doing (1) would match the way that sha1_object_info_extended()
works. But it would mean that every caller would have to
initialize the object_context, which they don't currently
have to do.

This patch does (2), and adds a new bit to the function's
flags field. All of the callers that look at the "path"
field are updated to pass the new flag.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King
2017-05-19 08:54:43 -04:00
committed by Junio C Hamano
parent d72cae12b9
commit dc944b65f1
5 changed files with 24 additions and 8 deletions

View File

@ -61,7 +61,8 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
if (unknown_type)
flags |= LOOKUP_UNKNOWN_OBJECT;
if (get_sha1_with_context(obj_name, 0, oid.hash, &obj_context))
if (get_sha1_with_context(obj_name, GET_SHA1_RECORD_PATH,
oid.hash, &obj_context))
die("Not a valid object name %s", obj_name);
if (!path)
@ -165,6 +166,7 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
die("git cat-file %s: bad file", obj_name);
write_or_die(1, buf, size);
free(obj_context.path);
return 0;
}