view tests/test-simplemerge.py.out @ 35450:e31773898197

run-tests: use context managers for file descriptors

I've seen the following error a few times recently when running the tests with
`yes | ./run-tests.py --local -j9 -i`:

Errored test-add.t: Traceback (most recent call last):
  File "./run-tests.py", line 821, in run
    self.runTest()
  File "./run-tests.py", line 910, in runTest
    if self._result.addOutputMismatch(self, ret, out, self._refout):
  File "./run-tests.py", line 1774, in addOutputMismatch
    rename(test.errpath, test.path)
  File "./run-tests.py", line 571, in rename
    os.remove(src)
WindowsError: [Error 32] The process cannot access the file because it is being
 used by another process: 'c:\\Users\\Matt\\projects\\hg\\tests\\test-add.t.err'

This change doesn't fix the problem, but it seems like a simple enough
improvement.

................
----------------------------------------------------------------------
Ran 16 tests in 0.000s

OK