tests/test-fncache.t

setdiscovery: fix hang when #heads>200 (issue2971)

When setting up the next sample, we always add all of the heads, regardless
of the desired max sample size. But if the number of heads exceeds this
size, then we don't add any more nodes from the still undecided set.
(This is debatable per se, and I'll investigate it, but it's how we designed
it at the moment.)

The bug was that we always added the overall heads, not the heads of the
remaining undecided set. Thus, if #heads>200 (desired sample size), we
did not make progress any longer.

Init repo1:

  $ hg init repo1
  $ cd repo1
  $ echo "some text" > a
  $ hg add
  adding a
  $ hg ci -m first
  $ cat .hg/store/fncache | sort
  data/a.i

Testing a.i/b:

  $ mkdir a.i
  $ echo "some other text" > a.i/b
  $ hg add
  adding a.i/b
  $ hg ci -m second
  $ cat .hg/store/fncache | sort
  data/a.i
  data/a.i.hg/b.i

Testing a.i.hg/c:

  $ mkdir a.i.hg
  $ echo "yet another text" > a.i.hg/c
  $ hg add
  adding a.i.hg/c
  $ hg ci -m third
  $ cat .hg/store/fncache | sort
  data/a.i
  data/a.i.hg.hg/c.i
  data/a.i.hg/b.i

Testing verify:

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  3 files, 3 changesets, 3 total revisions

  $ rm .hg/store/fncache

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
   data/a.i@0: missing revlog!
   data/a.i.hg/c.i@2: missing revlog!
   data/a.i/b.i@1: missing revlog!
  3 files, 3 changesets, 3 total revisions
  3 integrity errors encountered!
  (first damaged changeset appears to be 0)
  [1]
  $ cd ..

Non store repo:

  $ hg --config format.usestore=False init foo
  $ cd foo
  $ mkdir tst.d
  $ echo foo > tst.d/foo
  $ hg ci -Amfoo
  adding tst.d/foo
  $ find .hg | sort
  .hg
  .hg/00changelog.i
  .hg/00manifest.i
  .hg/data
  .hg/data/tst.d.hg
  .hg/data/tst.d.hg/foo.i
  .hg/dirstate
  .hg/last-message.txt
  .hg/requires
  .hg/undo
  .hg/undo.bookmarks
  .hg/undo.branch
  .hg/undo.desc
  .hg/undo.dirstate
  $ cd ..

Non fncache repo:

  $ hg --config format.usefncache=False init bar
  $ cd bar
  $ mkdir tst.d
  $ echo foo > tst.d/Foo
  $ hg ci -Amfoo
  adding tst.d/Foo
  $ find .hg | sort
  .hg
  .hg/00changelog.i
  .hg/dirstate
  .hg/last-message.txt
  .hg/requires
  .hg/store
  .hg/store/00changelog.i
  .hg/store/00manifest.i
  .hg/store/data
  .hg/store/data/tst.d.hg
  .hg/store/data/tst.d.hg/_foo.i
  .hg/store/undo
  .hg/undo.bookmarks
  .hg/undo.branch
  .hg/undo.desc
  .hg/undo.dirstate
  $ cd ..