Make parse_loose_header() return error codes and data instead of
invoking die() by itself.
For now we'll move the relevant die() call to loose_object_info() and
read_loose_object() to keep this change smaller. In a subsequent
commit we'll make read_loose_object() return an error code instead of
dying. We should also address the "allow_unknown" case (should be
moved to builtin/cat-file.c), but for now I'll be leaving it.
For making parse_loose_header() not die() change its prototype to
accept a "struct object_info *" instead of the "unsigned long *sizep"
it accepted before. Its callers can now check the populated populated
"oi->typep".
Because of this we don't need to pass in the "unsigned int flags"
which we used for OBJECT_INFO_ALLOW_UNKNOWN_TYPE, we can instead do
that check in loose_object_info().
This also refactors some confusing control flow around the "status"
variable. In some cases we set it to the return value of "error()",
i.e. -1, and later checked if "status < 0" was true.
Since 93cff9a978e (sha1_loose_object_info: return error for corrupted
objects, 2017-04-01) the return value of loose_object_info() (then
named sha1_loose_object_info()) had been a "status" variable that be
any negative value, as we were expecting to return the "enum
object_type".
The only negative type happens to be OBJ_BAD, but the code still
assumed that more might be added. This was then used later in
e.g. c84a1f3ed4d (sha1_file: refactor read_object, 2017-06-21). Now
that parse_loose_header() will return 0 on success instead of the
type (which it'll stick into the "struct object_info") we don't need
to conflate these two cases in its callers.
Since parse_loose_header() doesn't need to return an arbitrary
"status" we only need to treat its "ret < 0" specially, but can
idiomatically overwrite it with our own error() return. This along
with having made unpack_loose_header() return an "enum
unpack_loose_header_result" in an earlier commit means that we can
move the previously nested if/else cases mostly into the "ULHR_OK"
branch of the "switch" statement.
We should be less silent if we reach that "status = -1" branch, which
happens if we've got trailing garbage in loose objects, see
f6371f92104 (sha1_file: add read_loose_object() function, 2017-01-13)
for a better way to handle it. For now let's punt on it, a subsequent
commit will address that edge case.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
---
cache.h | 11 +++++++--
object-file.c | 67 +++++++++++++++++++++++++--------------------------
streaming.c | 3 ++-
3 files changed, 44 insertions(+), 37 deletions(-)
diff --git a/cache.h b/cache.h
index 8e05392fda8..6c5f00c82d5 100644
--- a/cache.h
+++ b/cache.h
@@ -1349,9 +1349,16 @@ enum unpack_loose_header_result unpack_loose_header(git_zstream *stream,
unsigned long bufsiz,
struct strbuf *hdrbuf);
+/**
+ * parse_loose_header() parses the starting "<type> <len>\0" of an
+ * object. If it doesn't follow that format -1 is returned. To check
+ * the validity of the <type> populate the "typep" in the "struct
+ * object_info". It will be OBJ_BAD if the object type is unknown. The
+ * parsed <len> can be retrieved via "oi->sizep", and from there
+ * passed to unpack_loose_rest().
+ */
struct object_info;
-int parse_loose_header(const char *hdr, struct object_info *oi,
- unsigned int flags);
+int parse_loose_header(const char *hdr, struct object_info *oi);
int check_object_signature(struct repository *r, const struct object_id *oid,
void *buf, unsigned long size, const char *type);
diff --git a/object-file.c b/object-file.c
index 3589c5a2e33..a70669700d0 100644
--- a/object-file.c
+++ b/object-file.c
@@ -1369,8 +1369,7 @@ static void *unpack_loose_rest(git_zstream *stream,
* too permissive for what we want to check. So do an anal
* object header parse by hand.
*/
-int parse_loose_header(const char *hdr, struct object_info *oi,
- unsigned int flags)
+int parse_loose_header(const char *hdr, struct object_info *oi)
{
const char *type_buf = hdr;
unsigned long size;
@@ -1392,15 +1391,6 @@ int parse_loose_header(const char *hdr, struct object_info *oi,
type = type_from_string_gently(type_buf, type_len, 1);
if (oi->type_name)
strbuf_add(oi->type_name, type_buf, type_len);
- /*
- * Set type to 0 if its an unknown object and
- * we're obtaining the type using '--allow-unknown-type'
- * option.
- */
- if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
- type = 0;
- else if (type < 0)
- die(_("invalid object type"));
if (oi->typep)
*oi->typep = type;
@@ -1427,7 +1417,14 @@ int parse_loose_header(const char *hdr, struct object_info *oi,
/*
* The length must be followed by a zero byte
*/
- return *hdr ? -1 : type;
+ if (*hdr)
+ return -1;
+
+ /*
+ * The format is valid, but the type may still be bogus. The
+ * Caller needs to check its oi->typep.
+ */
+ return 0;
}
static int loose_object_info(struct repository *r,
@@ -1441,6 +1438,7 @@ static int loose_object_info(struct repository *r,
char hdr[MAX_HEADER_LEN];
struct strbuf hdrbuf = STRBUF_INIT;
unsigned long size_scratch;
+ enum object_type type_scratch;
int allow_unknown = flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE;
if (oi->delta_base_oid)
@@ -1472,6 +1470,8 @@ static int loose_object_info(struct repository *r,
if (!oi->sizep)
oi->sizep = &size_scratch;
+ if (!oi->typep)
+ oi->typep = &type_scratch;
if (oi->disk_sizep)
*oi->disk_sizep = mapsize;
@@ -1479,6 +1479,18 @@ static int loose_object_info(struct repository *r,
switch (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr),
allow_unknown ? &hdrbuf : NULL)) {
case ULHR_OK:
+ if (parse_loose_header(hdrbuf.len ? hdrbuf.buf : hdr, oi) < 0)
+ status = error(_("unable to parse %s header"), oid_to_hex(oid));
+ else if (!allow_unknown && *oi->typep < 0)
+ die(_("invalid object type"));
+
+ if (!oi->contentp)
+ break;
+ *oi->contentp = unpack_loose_rest(&stream, hdr, *oi->sizep, oid);
+ if (*oi->contentp)
+ goto cleanup;
+
+ status = -1;
break;
case ULHR_BAD:
status = error(_("unable to unpack %s header"),
@@ -1490,31 +1502,16 @@ static int loose_object_info(struct repository *r,
break;
}
- if (status < 0) {
- /* Do nothing */
- } else if (hdrbuf.len) {
- if ((status = parse_loose_header(hdrbuf.buf, oi, flags)) < 0)
- status = error(_("unable to parse %s header with --allow-unknown-type"),
- oid_to_hex(oid));
- } else if ((status = parse_loose_header(hdr, oi, flags)) < 0)
- status = error(_("unable to parse %s header"), oid_to_hex(oid));
-
- if (status >= 0 && oi->contentp) {
- *oi->contentp = unpack_loose_rest(&stream, hdr,
- *oi->sizep, oid);
- if (!*oi->contentp) {
- git_inflate_end(&stream);
- status = -1;
- }
- } else
- git_inflate_end(&stream);
-
+ git_inflate_end(&stream);
+cleanup:
munmap(map, mapsize);
if (oi->sizep == &size_scratch)
oi->sizep = NULL;
strbuf_release(&hdrbuf);
+ if (oi->typep == &type_scratch)
+ oi->typep = NULL;
oi->whence = OI_LOOSE;
- return (status < 0) ? status : 0;
+ return status;
}
int obj_read_use_lock = 0;
@@ -2585,6 +2582,7 @@ int read_loose_object(const char *path,
git_zstream stream;
char hdr[MAX_HEADER_LEN];
struct object_info oi = OBJECT_INFO_INIT;
+ oi.typep = type;
oi.sizep = size;
*contents = NULL;
@@ -2601,12 +2599,13 @@ int read_loose_object(const char *path,
goto out;
}
- *type = parse_loose_header(hdr, &oi, 0);
- if (*type < 0) {
+ if (parse_loose_header(hdr, &oi) < 0) {
error(_("unable to parse header of %s"), path);
git_inflate_end(&stream);
goto out;
}
+ if (*type < 0)
+ die(_("invalid object type"));
if (*type == OBJ_BLOB && *size > big_file_threshold) {
if (check_stream_oid(&stream, hdr, *size, path, expected_oid) < 0)
diff --git a/streaming.c b/streaming.c
index bd89c50e7b3..fe54665d86e 100644
--- a/streaming.c
+++ b/streaming.c
@@ -225,6 +225,7 @@ static int open_istream_loose(struct git_istream *st, struct repository *r,
{
struct object_info oi = OBJECT_INFO_INIT;
oi.sizep = &st->size;
+ oi.typep = type;
st->u.loose.mapped = map_loose_object(r, oid, &st->u.loose.mapsize);
if (!st->u.loose.mapped)
@@ -238,7 +239,7 @@ static int open_istream_loose(struct git_istream *st, struct repository *r,
case ULHR_TOO_LONG:
goto error;
}
- if (parse_loose_header(st->u.loose.hdr, &oi, 0) < 0)
+ if (parse_loose_header(st->u.loose.hdr, &oi) < 0 || *type < 0)
goto error;
st->u.loose.hdr_used = strlen(st->u.loose.hdr) + 1;
--
2.33.0.1375.g5eed55aa1b5
