Re: [PATCH] Fix delta integer overflows
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Aug 8, 2017, 01:44 UTC
- Message-ID
- <xmqqvalyn89b.fsf@gitster.mtv.corp.google.com>
- In-Reply-To
- <xmqq1sonql76.fsf@gitster.mtv.corp.google.com>
Junio C Hamano <gitster@pobox.com> writes:
Show 26 quoted lines
> Martin Koegler <martin.koegler@chello.at> writes: > >> From: Martin Koegler <martin.koegler@chello.at> >> >> The current delta code produces incorrect pack objects for files > 4GB. >> >> Signed-off-by: Martin Koegler <martin.koegler@chello.at> >> --- >> diff-delta.c | 23 ++++++++++++----------- >> 1 file changed, 12 insertions(+), 11 deletions(-) >> >> Just pass any file > 4 GB to the delta-compression [by increasing the delta limits]. >> As file size, a truncated 32bit value will be encoded, leading to broken pack files. > > The patch obviously makes the code better and self consistent in > that "struct delta_index" has src_size as ulong, and this function > takes trg_size as ulong, and it was plain wrong for the code to > assume that "i", which is uint, can receive it safely. > > In the longer term we might want to move to size_t or even > uintmax_t, as the ulong on a platform may not be long enough in > order to express the largest file size the platform can have, but > this patch (1) is good even without such a change, and (2) gives a > good foundation to build on if we want such a change on top. > > Thanks. Will queue.
Having said that, I am a bit curious how you came to this patch. Was the issue found by code inspection, or did you actually have a real life use case to raise the core.bigFileThreshold configuration to a value above 4GB?
Thanks.