context: use a the nofsauditor when matching file in history (issue4749) Before this change, asking for file from history (eg: 'hg cat -r 42 foo/bar') could fail because of the current content of the working copy (eg: current "foo" being a symlink). As the working copy state have no influence on the content of the history, we can safely skip these checks. The working copy context class have a different 'match' implementation. That implementation still use the repo.auditor will still catch symlink traversal. I've audited all stuff calling "match" and they all go through a ctx in a sensible way. The most unclear case was diff which still seemed okay. You raised my paranoid level today and I double checked through tests. They behave properly. The odds of someone using the wrong (matching with a changectx for operation that will eventually touch the file system) is non-zero because you are never sure of what people will do. But I dunno if we can fight against that. So I would not commit to "never" for "at this level" and "in the future" if someone write especially bad code. However, as a last defense, the vfs itself is running path auditor in all cases outside of .hg/. So I think anything passing the 'matcher' for buggy reason would growl at the vfs layer.

  $ hg init

  $ echo 123 > a
  $ hg add a
  $ hg commit -m "first" a

  $ mkdir sub
  $ echo 321 > sub/b
  $ hg add sub/b
  $ hg commit -m "second" sub/b

  $ cat sub/b
  321

  $ hg co 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ cat sub/b 2>/dev/null || echo "sub/b not present"
  sub/b not present

  $ test -d sub || echo "sub not present"
  sub not present