tests/test-pull-pull-corruption2.t

windows: sanity-check symlink placeholders

On Windows, we store symlinks as plain files with the link contents.
Via user error or NFS/Samba assistance, these files often end up with
'normal' file contents. Committing these changes thus gives an
invalid symlink that can't be checked out on Unix.

Here we filter out any modified symlink placeholders that look
suspicious when computing status:

- more than 1K (looks more like a normal file)
- contain NULs (not allowed on Unix, probably a binary)
- contains \n (filenames can't contain \n, very unusual for symlinks,
  very common for files)

Corrupt an hg repo with two pulls.
create one repo with a long history

  $ hg init source1
  $ cd source1
  $ touch foo
  $ hg add foo
  $ for i in 1 2 3 4 5 6 7 8 9 10; do
  >     echo $i >> foo
  >     hg ci -m $i
  > done
  $ cd ..

create a third repo to pull both other repos into it

  $ hg init version2
  $ hg -R version2 pull source1 &
  $ sleep 1
  pulling from source1
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 10 changesets with 10 changes to 1 files
  (run 'hg update' to get a working copy)
  $ hg clone --pull -U version2 corrupted
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 10 changesets with 10 changes to 1 files
  $ wait
  $ hg -R corrupted verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 10 changesets, 10 total revisions
  $ hg -R version2 verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 10 changesets, 10 total revisions