[MERGE] Fix for Bug 129299, BZR_PLUGIN_PATH should ignore trailiing slashes.

[Blake Winton]

Robert Collins wrote:
> Robert Collins has voted resubmit.
> Status is now: Resubmit
> Comment:
> Couple of things. If load_from_path is now accepting paths with '/', 
> then you shouldn't need to santise BZR_PLUGINS_PATH - the lower level 
> check will suffice.

I thought that, but set_plugins_path seems to get called from 
__init__.py without a following call to load_from_path.

Is load_from_path guaranteed to be called to load a plugin, or is there 
another way someone could access plugins.__path__?  (i.e. from plugins 
import xxx...)  Alternatively, if we're not using plugins.__path__, why 
do we set it?

bzrlib/plugin.py says at lines 27-29:
BZR_PLUGIN_PATH is also honoured for any plugins imported via
'import bzrlib.plugins.PLUGINNAME', as long as set_plugins_path has been
called.
But that won't work unless we sanitize plugins.__path__ since it doesn't 
call load_from_dirs.  (I also thought about doing the check only in 
set_plugins_path, but tests for load_from_dirs which pass in a set of 
directories don't necessarily call set_plugins_path, and so wouldn't get 
sanitized.)

I guess, in the end, I just felt "hinky" about storing an invalid path 
in plugins.__path__, since Python could try to use it for something.  If 
you think that's okay, I'ld be more than happy to only sanitize the data 
once, in load_from_path.

 > Finally, your test that
> load_from_path works with '/' is clearly cargo culted - I suggest you 
> read through it once and make sure the comments match what your test 
> actually does - the don't currently.

Yup.  I believe I've fixed it now.

I'll resubmit after I get a response to the first question above.

Later,
Blake.