bug#24126: vc-hg-state can be extremely slow

[Jonathan Kotta]

On Tue, Aug 2, 2016 at 8:32 AM, Dmitry Gutov <dgutov@yandex.ru> wrote:

On 08/01/2016 09:40 PM, Jonathan Kotta wrote:

Emacs uses `hg status -A` in vc-hg-state, which in turn is used in many
vc commands (e.g. vc-root-diff).  The "-A" option makes mercurial look
at all files under the directory, even the ignored ones.  If there are a
lot of ignored files, this will be very slow.

Why does it do that? We're passing a specific file name to it.

In the case of `vc-root-diff` at least, it's passing in a directory; the command is essentially `hg status -A ./`, and the CWD is indeed the repo root.  I did this by running `vc-root-diff` from a dired buffer visiting the repo root.

--

Thanks,

Jonathan Kotta

Hofstadter's Law:
    It always takes longer than you expect, even
    when you take into account Hofstadter's Law.