[PATCH 1 of 2 V2] dirstate: add an extension hook for interesting files

[Matt Mackall]

On Mon, 2013-05-13 at 12:47 -0700, Siddharth Agarwal wrote:
> # HG changeset patch
> # User Siddharth Agarwal <sid0 at fb.com>
> # Date 1366675878 25200
> #      Mon Apr 22 17:11:18 2013 -0700
> # Node ID ed4040d92e56cd7a963f896f72bcf55922449171
> # Parent  0a031b2198905fed27a2c5adbda215c7907d3cea
> dirstate: add an extension hook for interesting files
> 
> Consider a hypothetical extension that implements walk in a more efficient
> manner and return only files that status would consider interesting. However,
> that can only be done under some situations, such as when clean files are
> not being asked for and a match.traversedir callback is not set. The
> interesting flag lets walk tell these two cases apart.

The semantics of this flag are extremely confusing. I think it'd be
better to have a flag like this:

 full: if true, do a full walk (default)
       if false, allow skipping known-clean files

-- 
Mathematics is the supreme nostalgia of our time.