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.

import sys

globalvars = {}
lines = sys.stdin.readlines()
while lines:
    l = lines.pop(0)
    if l.startswith('SALT'):
        print(l[:-1])
    elif l.startswith('>>> '):
        snippet = l[4:]
        while lines and lines[0].startswith('... '):
            l = lines.pop(0)
            snippet += l[4:]
        c = compile(snippet, '<heredoc>', 'single')
        try:
            exec(c, globalvars)
        except Exception as inst:
            print(repr(inst))