Re: [RFC PATCH 06/15] Automatically reuse sparse limiting arguments in revision walking

On Sun, Sep 5, 2010 at 10:13 AM, Elijah Newren [off-list ref] wrote:

In a sparse repository, by automatically making use of sparse limits
specified at clone time, we can avoid walking uninteresting commits and
prevent access to missing trees and blobs.  Note that this means that if
you created a sparse clone with
 git clone <repo> <dest_dir> -- PATH1 PATH2 PATH3 PATH4 PATH5
then
 git log
implicitly runs as though you had manually specified
 git log -- PATH1 PATH2 PATH3 PATH4 PATH5
Similarly, running
 git diff
implicitly runs as though you had manually specified
 git diff -- PATH1 PATH2 PATH3 PATH4 PATH5

This is necessary for proper operation of git diff in a sparse clone to
avoid accessing missing objects.  In the case of a plain git log, this
merely serves as an additional convenience, but for more complicated log
operations (e.g. when passing -p or -S options) it becomes necessary.

I have a nicer approach here. Instead of modifying setup_revisions()
and similar functions, I update get_pathspec() to rewrite the
pathspecs from command line in narrow/shallow repos. get_pathspec()
currently does some form of rewriting already (prepending prefix).

So if you do "git log", get_pathspec() would return "git log -- PATH1
PATH2...". Will repost my series soon, or I can send that particular
patch to you.
-- 
Duy