only add value to hash if attr_element hash text

[hermesdt]

The gem was raising an exception when in the callback there are elements without content, like:

<Element />

In those cases the following is raised:

undefined method `lstrip' for nil:NilClass

Regards.

[kbeckman]

Thanks, @hermesdt! Sorry for the delay in getting to this one, but I've been pretty slammed at work and this particular change required me to think about a better overall testing strategy in onmiauth-wsfed. As you probably noticed, all of the XPath parsing in auth_callback.rb is tested using an actual XML file representation from an Azure ACS token... ...and it didn't account for the issue you discovered.

I plan on getting this in over the weekend... I'm working on the testing strategy now so I can better respond to issues like this one in the future.

[kbeckman]

@hermestd, I've been working on some refactoring tasks before I merge this in... I'm building in support to handle multiple token types (not just SAML 2.0). See this issue for more details if you're interested.

I have a couple of quick questions about your PR... What token issuer (Azure ACS, ADFS, something else) you were using when it generated an empty <Attribute>? Was it a non-optional claim that just didn't have a value?

If I'm correct, you got something that looked like this with no <AttributeValue>?

<AttributeElement name="http://xmlsoap.org/some/uri/detail" />

And if you don't mind, could you post an example token (complete wresult XML from the callback) to this thread so I can take a look at it? I'd like to be able to compare an authentication from your token issuer with one from Azure ACS just so I can see if there might be some other things similar to the issue you found that might not have popped up yet... Thanks!