Cannot have multiple child elements with a default namespace

[jnunemaker]

HappyMapper 0.2.2 (commit 545ebcd8a8b6dec66a526244321fc1dfb171de05) libxml 0.9.8

If an object including HappyMapper has multiple child elements (via has_one or has_many) and a default namespace, an exception is raised when processing the second child element.

I’ve recreated the issue in the specs, see attached diff.

It seems trying to assign a default namespace prefix to a node fails in libxml, but HappyMapper should probably not try to do this anyway.

I’ve fixed this ticket with http://github.com/lightningdb/happymapper/commit/ac6510bcec0314435d29ae092e857e965c0e1c28

The issue is that libxml falls over if the default prefix is assigned more than once. Seems to be a bug with libxml, but likewise it is probably something that happymapper should avoid anyway.

So before assigning the default prefix, we check whether a default prefix has already been assigned.

I’ve updated the tests to reflect this situation, by adding an extra ‘has_one’, which invokes the nested parsing that caused the error in the first place. I moved the Address class mapper definition up and added an address node to the product (I realise this doesn’t make ‘domain’ sense, but it proves the issue and the fix).

Hopefully John approves and can pull into the main happymapper?