[PATCH] minifileset: allow 'path:' patterns to have an explicit trailing slash

[Yuya Nishihara]

On Tue, 13 Feb 2018 07:58:50 -0500, Matt Harbison wrote:
> 
> > On Feb 13, 2018, at 6:27 AM, Yuya Nishihara <yuya at tcha.org> wrote:
> > 
> >> On Mon, 12 Feb 2018 22:17:35 -0500, Matt Harbison wrote:
> >> # HG changeset patch
> >> # User Matt Harbison <matt_harbison at yahoo.com>
> >> # Date 1518488713 18000
> >> #      Mon Feb 12 21:25:13 2018 -0500
> >> # Node ID e99e6917138593d2dddf7e0f5506dbd3f6c87743
> >> # Parent  9b5df6e19a4f308e14703a8136cd0530c1e1d1a9
> >> minifileset: allow 'path:' patterns to have an explicit trailing slash
> >> 
> >> We allow for it on the command line, with `hg status`, for example.  I thought
> >> that I copied this "n.startswith(p) and (len(n) == pl or n[pl] == '/')" pattern
> >> from somewhere, but I don't see it now.
> >> 
> >> diff --git a/mercurial/minifileset.py b/mercurial/minifileset.py
> >> --- a/mercurial/minifileset.py
> >> +++ b/mercurial/minifileset.py
> >> @@ -26,7 +26,7 @@
> >>                     raise error.ParseError(_('reserved character: %s') % c)
> >>             return lambda n, s: n.endswith(ext)
> >>         elif name.startswith('path:'): # directory or full path test
> >> -            p = name[5:] # prefix
> >> +            p = name[5:] if name[-1] != '/' else name[5:-1] # prefix
> > 
> > Doesn't it mean 'a/' matches 'a'?
> 
> Yes. (But 'a' won’t match 'ab'.)

Ugh, I never thought 'path:hg/' would match the file 'hg', but it does
probably because of util.normpath().

  % hg debugwalk 'path:hg/'
  matcher: <patternmatcher patterns='(?:hg(?:/|$))'>
  f  hg  hg  exact

Perhaps applying normpath() would look saner than testing if name[-1] == '/'.

> Basically, I spent some time last week writing ignore rules for some converted repos, and got into the habit of appending a trailing '/' to ensure the match is a directory, and not just a substring.  When I did that here, it took awhile to figure out why the path was being ignored.  ('path:' only matches directories)
> 
> > Can't we reuse some parts of the match module to build a function or regexp
> > from a pattern string?
> 
> Probably.  I’ve seen a couple cases where a regex pattern would be useful.  I just assumed those other match types were part of the performance concern that was the reason for splitting out the mini language in the first place.

(CC Jun)

I think the O(n) concern came from how fileset filters n-length list, not
from the matcher function itself.