1. Stefan Saasen
  2. git


Linus Torvalds  committed 9130ac1

Better error messages for corrupt databases

This fixes another problem that Andy's case showed: git-fsck-objects
reports nonsensical results for corrupt objects.

There were actually two independent and confusing problems:

- when we had a zero-sized file and used map_sha1_file, mmap() would
return EINVAL, and git-fsck-objects would report that as an insane and
confusing error. I don't know when this was introduced, it might have
been there forever.

- when "parse_object()" returned NULL, fsck would say "object not found",
which can be very confusing, since obviously the object might "exist",
it's just unparseable because it's totally corrupt.

So this just makes "xmmap()" return NULL for a zero-sized object (which is
a valid thing pointer, exactly the same way "malloc()" can return NULL for
a zero-sized allocation). That fixes the first problem (but we could have
fixed it in the caller too - I don't personally much care whichever way it
goes, but maybe somebody should check that the NO_MMAP case does
something sane in this case too?).

And the second problem is solved by just making the error message slightly
clearer - the failure to parse an object may be because it's missing or
corrupt, not necessarily because it's not "found".

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

  • Participants
  • Parent commits 93c1e07
  • Branches master

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Files changed (2)

File fsck-objects.c

View file
  • Ignore whitespace
 	struct object *obj = parse_object(sha1);
 	if (!obj)
-		return error("%s: object not found", sha1_to_hex(sha1));
+		return error("%s: object corrupt or missing", sha1_to_hex(sha1));
 	if (obj->flags & SEEN)
 		return 0;
 	obj->flags |= SEEN;

File git-compat-util.h

View file
  • Ignore whitespace
 	void *ret = mmap(start, length, prot, flags, fd, offset);
 	if (ret == MAP_FAILED) {
+		if (!length)
+			return NULL;
 		ret = mmap(start, length, prot, flags, fd, offset);
 		if (ret == MAP_FAILED)