Avoid collapsing slashes that follow http or https

[robolson]

urlnorm is breaking a legitimate use of two successive slashes in our URLs.

Here is an example of what is happening:

http://example.com/login?redirect-back-to=http://example.com/homepage

urlnorm'd is http://example.com/login?redirect-back-to=http:/example.com/homepage

@jehiah would you be open to adding a special case to not collapse two successive slashes that follow http: or https:? I am willing to put in a pull request for this but I wanted to check if it would be accepted first.

Ideally urlnorm would support all of the official URI schemas, not just http and https but since the list is large I think just checking http and https would satisfy 90% of people.

[jehiah]

Hi @robolson Thanks for writing up these details.

I would expect double slashes to be collapsed if they are in the path section of a URL, but not in the query string. I did a quick test (below) and it seems ok. Can you verify if you were seeing this happen in the path or query string or elsewhere?

>>> urlnorm.norm('http://example.com/login?redirect-back-to=http://example.com/homepage')
u'http://example.com/login?redirect-back-to=http://example.com/homepage'
>>> urlnorm.__version__
'1.1.2'

[robolson]

Ah! I'm sorry @jehiah. I brainstormed a simple example without testing it and and your right, urlnorm, does the right thing when the double slashes are in the query string.

In my real life case, the slashes are part of the path section of the URL. The URLs are intended for consumption by the Thumbor project which has architected the URLs to be created in this fashion.

Here is an example URL for Thumbor that is being sent through urlnorm:

>>> urlnorm.norm('http://thumbor-server.com/K97LekICOXT9MbO3X1u8BBkrjbu5/300x200/http://example.com/images/white-sunglasses.jpg')
u'http://thumbor-server.com/K97LekICOXT9MbO3X1u8BBkrjbu5/300x200/http:/example.com/images/white-sunglasses.jpg'

[jehiah]

gotcha. We are both on the same page now.

I'm totally not opposed to special casing this one exclusion to collapsing a double '//' in the path. Patch away.

My only implementation request is to include a test that has a comment w/ a decent one line explanation of why that's a common situation which is special cased. Then ping me when you have something to review/merge.