Re: [PATCH] cache-tree: do not cache empty trees

[Nguyen Thai Ngoc Duy <pclouds@gmail.com>]

On Mon, Feb 7, 2011 at 7:18 PM, Ilari Liusvaara
<ilari.liusvaara@elisanet.fi> wrote:
> On Mon, Feb 07, 2011 at 04:57:13PM +0700, Nguyen Thai Ngoc Duy wrote:
>>
>> Perhaps it's not a good approach after all. What I wanted was to make
>> pre-1.8.0 tolerate empty trees created by 1.8.0. Perhaps it's better
>> to just let pre-1.8.0 refuse to work with empty trees, forcing users
>> to upgrade to 1.8.0?
>>
>> The (untested) patch below would make git refuse to create an index
>> from a tree that contains empty trees. Hmm?
>
> Remember, many distros ship with old versions of Git. Debian stable
> is now at 1.7.2.3 (Squeeze became Debian 6.0) and it'll take years
> before next release. What about these?

Waiting a few years is my best bet :P Really I don't figure out any
other way for migration. New empty trees would end up in repository
and affect all connected clients regardless version.

> Making previous versions refuse to work with empty trees isn't exactly
> trivial, as the tree parser seems to be written to be extremely
> liberal on what it accepts.

The repository _can_ contain empty trees. The main problem is index
not supporting empty trees. I only prevent index being used. If users
create new commits (including empty trees) with mktree and
commit-tree, they can also checkout without index using ls-tree and
cat-file.
-- 
Duy