[PATCH v2 0/4] oe/path: three fixes plus selftest coverage

[Trevor Woerner <twoerner@gmail.com>]

While adding unit coverage for the copy of oe/path.py vendored into the
standalone wic repository, three real bugs turned up in the shared
meta/lib/oe/path.py. They are fixed here at the source so the whole
project benefits, each as its own standalone commit:

  - __realpath()'s isdir guard assigns a bare `false`, which is not a
    Python name; when os.path.isdir() raises, the handler meant to
    absorb the error raises NameError instead. Use the builtin False.
  - symlink(force=True) cleared the destination through remove(), which
    globs its argument; a destination containing glob metacharacters
    could fail to match itself (leaving a stale entry) or match
    unrelated files. Remove the literal destination instead.
  - canonicalize('') and canonicalize(None) returned the current
    working directory, because os.path.realpath('') does; a stray
    separator injected a spurious cwd entry too. Skip empty tokens.

The final commit extends meta/lib/oeqa/selftest/cases/liboe.py with a
PathTests class covering oe.path's own logic (join(), is_path_parent(),
symlink(), make_relative_symlink(), canonicalize(), which_wild(),
realpath()) and locking in the three fixes; backing any fix out turns
the matching test red. oe-selftest -r liboe.PathTests runs 46 tests,
all passing.

changes in v2:
  - No source changes; the three oe/path.py fixes are unchanged from v1.
  - Expand liboe.PathTests from 37 to 46 cases, mostly around the
    harder realpath() contracts (self-referential and A->B->A symlink
    loops both raising ELOOP, multi-component resolution under
    use_physdir, and the assume_dir ENOENT-vs-tolerated contract), plus
    a dangling symlink(), a make_relative_symlink() several directories
    below its target, and two more canonicalize() cases.

Trevor Woerner (4):
  oe/path: fix bare `false` NameError in __realpath's isdir guard
  oe/path: don't glob-expand the destination in symlink(force=True)
  oe/path: canonicalize('') should return '' rather than the cwd
  oeqa/selftest/liboe: cover oe.path's own path logic

 meta/lib/oe/path.py                   |  21 +-
 meta/lib/oeqa/selftest/cases/liboe.py | 376 ++++++++++++++++++++++++++
 2 files changed, 394 insertions(+), 3 deletions(-)

-- 
2.50.0.173.g8b6f19ccfc3a