Re: [PATCH v2 0/5] tree-walk object_id refactor

From: Junio C Hamano <gitster@pobox.com>
To: "brian m. carlson" <sandals@crustytoothpaste.net>
Cc: git@vger.kernel.org, "Martin Ågren" <martin.agren@gmail.com>,
	"Jeff King" <peff@peff.net>
Subject: Re: [PATCH v2 0/5] tree-walk object_id refactor
Date: Tue, 15 Jan 2019 09:51:54 -0800	[thread overview]
Message-ID: <xmqq8szlu7ut.fsf@gitster-ct.c.googlers.com> (raw)
In-Reply-To: <20190115003946.932078-1-sandals@crustytoothpaste.net> (brian m. carlson's message of "Tue, 15 Jan 2019 00:39:40 +0000")

"brian m. carlson" <sandals@crustytoothpaste.net> writes:

> There are a small number of places in our codebase where we cast a
> buffer of unsigned char to a struct object_id pointer. When we have
> GIT_MAX_RAWSZ set to 32 (because we have SHA-256), one of these places
> (the buffer for tree objects) can lead to us copying too much data when
> using SHA-1 as the hash, since there are only 20 bytes to read.

Thanks.  And thanks for a pleasant-to-follow discussion during the
review of the previous round.

> Changes from v1:
> * Use hashcpy instead of memcpy.
> * Adopt Peff's suggestion for improving patch 3.
>
> brian m. carlson (5):
>   tree-walk: copy object ID before use
>   match-trees: compute buffer offset correctly when splicing
>   match-trees: use hashcpy to splice trees
>   tree-walk: store object_id in a separate member
>   cache: make oidcpy always copy GIT_MAX_RAWSZ bytes
>
>  builtin/grep.c                     |  8 ++++----
>  builtin/merge-tree.c               | 20 ++++++++++----------
>  builtin/pack-objects.c             |  4 ++--
>  builtin/reflog.c                   |  4 ++--
>  cache-tree.c                       |  4 ++--
>  cache.h                            |  2 +-
>  contrib/coccinelle/object_id.cocci | 30 ------------------------------
>  delta-islands.c                    |  2 +-
>  fsck.c                             |  4 ++--
>  http-push.c                        |  4 ++--
>  list-objects.c                     |  6 +++---
>  match-trees.c                      | 27 ++++++++++++++++++++-------
>  notes.c                            |  4 ++--
>  packfile.c                         |  2 +-
>  revision.c                         |  4 ++--
>  tree-diff.c                        |  6 +++---
>  tree-walk.c                        | 21 ++++++++++++---------
>  tree-walk.h                        |  9 ++++++---
>  tree.c                             | 10 +++++-----
>  unpack-trees.c                     |  6 +++---
>  walker.c                           |  4 ++--
>  21 files changed, 85 insertions(+), 96 deletions(-)