Reversing a URL with optional arguments fails

[Rob Hudson]

I discovered this recently where I wanted a URL to be /detail/ for page 1, and /detail/page-2/ for further pages. I set up the "page-2/" as an optional regular expression and my default had a default kwarg. Reversing this URL without the page worked but not when I added the page argument. So I created some test cases and found some interesting results...

The first test case without the '$' terminated URL, results in:
AssertionError: '/optional/1/2' != '/optional/1/2/'

With the '$' terminated URL, it results in an exception, which is what I was triggering in my project, it seems:
AssertionError: '/optional/1/2/' != <class 'django.core.urlresolvers.NoReverseMatch'>

I'll attach the testing changes...

[Rob Hudson]

The 2nd patch moves the trailing slash out of the named group and the added tests now pass. I'm attaching if these extra tests are something that might be added to the resolving tests.

[Aymeric Augustin]

Change UI/UX from NULL to False.

[Aymeric Augustin]

Change Easy pickings from NULL to False.

[Bas Peschier]

The reason the tests failed with the slash inside the capturing group was that you should add the slash to the group in the reverse args/kwargs.

The second patch runs smoothly against master, probably fixed somewhere between then and now.

I am including the tests as part of the tests/documentation of #13525