Issue 19711: add test for changed portions after reloading a namespace package

http://bugs.python.org/msg202660

A related addition (Lib/test/test_importlib/test_api.py - test_reload_namespace_changed):

changeset:   86819:88c3a1a3c2ff3c3ab3f2bd77f0d5d5e5c1b37afa
parent:      86816:13a05ed33cf7
user:        Eric Snow <ericsnowcurrently@gmail.com>
date:        Thu Oct 31 22:22:15 2013 -0600
summary:     Issue #19413: Restore pre-3.3 reload() semantics of re-finding modules.

Here's a patch that adds the test.  However, the test is failing and my gut's telling me it's a legitimate failure.  I'll verify as soon as I have a chance and open a new issue if it is legit (i.e. a regression in 3.4, albeit an unlikely corner case).  Thanks for suggesting the test, Nick!

Well, the same patch (modulo adjusting to apply cleanly) fails in exactly the same way in 3.3.  So either the test isn't right or namespace packages have never supported reload in this way.  I'll keep investigating.

Regarding this issue, keep in mind that namespace packages have a dynamic __path__ which already updates (effectively) when new portions are added to sys.path.  So we just need to make sure that reloading does not break that.

To that end, here's a much simpler patch (with passing tests) that verifies that PEP 451 did not break anything here.

Latest patch LGTM.  Can we have a patch review please as #18864 is dependent on this.

Do we still need this patch, Eric?

To echo Brett's question, do we still need this patch, Eric?

New changeset c22ec7a45114 by Eric Snow in branch 'default':
Fixes #19711: Add tests for reloading namespace packages.
https://hg.python.org/cpython/rev/c22ec7a45114

I've gone ahead and pushed the patch.

stage: test needed -> resolved

messages: + msg236535

messages: + msg232568
versions: + Python 3.5, - Python 3.4

messages: + msg215144