tests/test-narrow-expanddirstate.t

revisions: allow "x123" to refer to nodeid prefix "123"

When resolving "123" to a revision, we try to interpret it as revnum
before we try to interpret it as a nodeid hex prefix. This can lead to
the shortest valid prefix being longer than necessary. This patch lets
us write such nodeids in a shorter form by prefixing them with "x"
instead of adding more hex digits until they're longer than the
longest decimal revnum.

On my hg repo with almost 69k revisions, turning this feature on saves
on average 0.4% on the average nodeid length. That clearly doesn't
justify this patch. However, it becomes more usefule when combined
with the earlier patches in this series that let you disambiguate
nodeid prefixes within a configured revset.

Note that we attempt to resolve symbols as nodeid prefixes after we've
exhausted all other posibilities, so this is a backwards compatible
change (only queries that would previously fail may now succeed).

I've still hidden this feature behind an experiemntal config option so
we can roll it back if needed.

Differential Revision: https://phab.mercurial-scm.org/D4041

  $ . "$TESTDIR/narrow-library.sh"

  $ hg init master
  $ cd master

  $ mkdir inside
  $ echo inside > inside/f1
  $ mkdir outside
  $ echo outside > outside/f2
  $ mkdir patchdir
  $ echo patch_this > patchdir/f3
  $ hg ci -Aqm 'initial'

  $ cd ..

  $ hg clone --narrow ssh://user@dummy/master narrow --include inside
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets dff6a2a6d433
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd narrow

  $ mkdir outside
  $ echo other_contents > outside/f2
  $ hg tracked | grep outside
  [1]
  $ hg files | grep outside
  [1]
  $ hg status

`hg status` did not add outside.
  $ hg tracked | grep outside
  [1]
  $ hg files | grep outside
  [1]

Unfortunately this is not really a candidate for adding to narrowhg proper,
since it depends on some other source for providing the manifests (when using
treemanifests) and file contents. Something like a virtual filesystem and/or
remotefilelog. We want to be useful when not using those systems, so we do not
have this method available in narrowhg proper at the moment.
  $ cat > "$TESTTMP/expand_extension.py" <<EOF
  > import os
  > import sys
  > 
  > from mercurial import encoding
  > from mercurial import extensions
  > from mercurial import localrepo
  > from mercurial import match as matchmod
  > from mercurial import narrowspec
  > from mercurial import patch
  > from mercurial import util as hgutil
  > 
  > def expandnarrowspec(ui, repo, newincludes=None):
  >   if not newincludes:
  >     return
  >   import sys
  >   newincludes = set([newincludes])
  >   includes, excludes = repo.narrowpats
  >   currentmatcher = narrowspec.match(repo.root, includes, excludes)
  >   includes = includes | newincludes
  >   if not repo.currenttransaction():
  >     ui.develwarn(b'expandnarrowspec called outside of transaction!')
  >   repo.setnarrowpats(includes, excludes)
  >   newmatcher = narrowspec.match(repo.root, includes, excludes)
  >   added = matchmod.differencematcher(newmatcher, currentmatcher)
  >   for f in repo[b'.'].manifest().walk(added):
  >     repo.dirstate.normallookup(f)
  > 
  > def wrapds(ui, repo, ds):
  >   class expandingdirstate(ds.__class__):
  >     @hgutil.propertycache
  >     def _map(self):
  >       ret = super(expandingdirstate, self)._map
  >       with repo.wlock(), repo.lock(), repo.transaction(
  >           b'expandnarrowspec'):
  >         expandnarrowspec(ui, repo,
  >                          encoding.environ.get(b'DIRSTATEINCLUDES'))
  >       return ret
  >   ds.__class__ = expandingdirstate
  >   return ds
  > 
  > def reposetup(ui, repo):
  >   class expandingrepo(repo.__class__):
  >     def _makedirstate(self):
  >       dirstate = super(expandingrepo, self)._makedirstate()
  >       return wrapds(ui, repo, dirstate)
  >   repo.__class__ = expandingrepo
  > 
  > def extsetup(unused_ui):
  >   def overridepatch(orig, ui, repo, *args, **kwargs):
  >     with repo.wlock():
  >       expandnarrowspec(ui, repo, encoding.environ.get(b'PATCHINCLUDES'))
  >       return orig(ui, repo, *args, **kwargs)
  > 
  >   extensions.wrapfunction(patch, b'patch', overridepatch)
  > EOF
  $ cat >> ".hg/hgrc" <<EOF
  > [extensions]
  > expand_extension = $TESTTMP/expand_extension.py
  > EOF

Since we do not have the ability to rely on a virtual filesystem or
remotefilelog in the test, we just fake it by copying the data from the 'master'
repo.
  $ cp -a ../master/.hg/store/data/* .hg/store/data
Do that for patchdir as well.
  $ cp -a ../master/patchdir .

`hg status` will now add outside, but not patchdir.
  $ DIRSTATEINCLUDES=path:outside hg status
  M outside/f2
  $ hg tracked | grep outside
  I path:outside
  $ hg files | grep outside > /dev/null
  $ hg tracked | grep patchdir
  [1]
  $ hg files | grep patchdir
  [1]

Get rid of the modification to outside/f2.
  $ hg update -C .
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

This patch will not apply cleanly at the moment, so `hg import` will break
  $ cat > "$TESTTMP/foo.patch" <<EOF
  > --- patchdir/f3
  > +++ patchdir/f3
  > @@ -1,1 +1,1 @@
  > -this should be "patch_this", but its not, so patch fails
  > +this text is irrelevant
  > EOF
  $ PATCHINCLUDES=path:patchdir hg import -p0 -e "$TESTTMP/foo.patch" -m ignored
  applying $TESTTMP/foo.patch
  patching file patchdir/f3
  Hunk #1 FAILED at 0
  1 out of 1 hunks FAILED -- saving rejects to file patchdir/f3.rej
  abort: patch failed to apply
  [255]
  $ hg tracked | grep patchdir
  [1]
  $ hg files | grep patchdir > /dev/null
  [1]

Let's make it apply cleanly and see that it *did* expand properly
  $ cat > "$TESTTMP/foo.patch" <<EOF
  > --- patchdir/f3
  > +++ patchdir/f3
  > @@ -1,1 +1,1 @@
  > -patch_this
  > +patched_this
  > EOF
  $ PATCHINCLUDES=path:patchdir hg import -p0 -e "$TESTTMP/foo.patch" -m message
  applying $TESTTMP/foo.patch
  $ cat patchdir/f3
  patched_this
  $ hg tracked | grep patchdir
  I path:patchdir
  $ hg files | grep patchdir > /dev/null