Re: support for large packs and 64-bit offsets

"Shawn O. Pearce" [off-list ref] writes:

Nicolas Pitre [off-list ref] wrote:
...
Here's something we didn't think about, but that occurred to me today
when reading this series: If we move the SHA-1 table out of the index
and into the packfile (like we are planning) dumb commit-walkers
(http-fetch) will have problems.  Right now they download the
indexes of every available packfile to determine if they need to
download the corresponding packfile to obtain a needed object.

If we really care about older dumb clients, one option is to
generate not .idx but .idx2, and have a corresponding .idx only
to support them.  But at that point, it's probably cleaner to
have an explicit option to produce .idx file of a particular
version, and tell people to pack public repositories they expect
older dumb clients to access with that option to keep things
backward compatible.