Re: VC and bzr.

[Stefan Monnier]

> Until and unless this is fixed, I think we should stop using "bzr
> status" for accessing VC-related information when we do file I/O.

There is code to parse the Bzr data "manually", so at least when opening
a file, we should be able to get the Bzr status info without
running Bzr.

> Or maybe we should access it lazily (it's not that seeing the
> up-to-date revno in the mode line is such a crucial feature), or
> somehow access it en masse, then cache it.

The revno is not important, indeed (maybe we should even stop
displaying it since it uses up precious modeline estate).

It's not the only info, tho:
- we also check&display whether or not the file is under Bzr control.
- we check&display whether it's locally edited or not.
- we run some hooks depending on the backend which may turn on smerge-mode

Note that with the proliferation of backends there is some pressure to
reduce the amount of work done per-backend when visiting a file.
So maybe we should completely stop checking the VC state when visiting
a file, and only do it when the user invokes VC.  This will mean that
the VC status won't appear in the modeline any more (or we could set it
up "in the background") and that we can't easily enable smerge-mode when
there are conflicts (unless we scan each and every file for diff3
markers).


        Stefan