Re: Public repro case! Re: [PATCH/RFC] Allow writing loose objects that are corrupted in a pack file

Linus Torvalds [off-list ref] wrote:

On Wed, 7 Jan 2009, R. Tyler Ballance wrote:

quoted

        tyler@grapefruit:~/source/git/linux-2.6> git pull
        error: failed to read object be1b87c70af69acfadb8a27a7a76dfb61de92643 at offset 1850923
        from .git/objects/pack/pack-dbe154052997a05499eb6b4fd90b924da68e799a.pack
        fatal: object be1b87c70af69acfadb8a27a7a76dfb61de92643 is corrupted

Btw, this is an interesting error message, mostly because of what is 
_not_ there.

In particular, it doesn't report any reason _why_ it failed to read the 
object, which as far as I can tell can happen for only one reason: 
unpack_compressed_entry() returns NULL, and that path is the only thing 
that can do so without a message.

And it only does it if zlib fails.

Ok, well, in this case I've been able to reproduce a zlib inflate
failure on the base object in a 2 deep delta chain.  We got back:

  #define Z_STREAM_ERROR (-2)

this causes the buffer to be freed and NULL to come back out of
unpack_compressed_entry(), and then everything is corrupt...

-- 
Shawn.