Re: [PATCH 2/9] Add flag to make unpack_trees() not print errors.

[Junio C Hamano <gitster@pobox.com>]

Daniel Barkalow <barkalow@iabervon.org> writes:

> On Tue, 5 Feb 2008, Johannes Schindelin wrote:
> ...
>> > Additionally, if unpack_trees() returns with an error, but without 
>> > printing anything, it will roll back any changes to the index (by 
>> > rereading the index, currently). This obviously could be done by the 
>> > caller, but chances are that the caller would forget and debugging this 
>> > is difficult.
>> 
>> Granted, it is easy to forget.  But maybe the caller does not need the 
>> index?  Or maybe it wants a different one?  I'd prefer the caller to clean 
>> up, if necessary.
>
> That's what makes it "gently" instead of just "silent"; it has no effect 
> if it doesn't succeed. Longer term, I'd like to have unpack_trees() unpack 
> into a separate index, which should actually be faster (since it doesn't 
> have to keep shifting the entries in the index it's working on) and make 
> this moot.

Absolutely.  That is the original motivation I did the_index
thing for.

But "re-reading" may not be quite nice.  It would defeat the
optimization introduced by the change to use CE_UPTODATE flag to
avoid unnecessary lstat(2) calls.