xml4r/libxml-ruby — pull request #54 by julp (2013-01-30 18:45:55+00:00)
Title: XML::Writer class multiple fixes

Hi,

I bring few fixes on XML::Writer class:
* hide/forbid instantiation with new (object is then unusable, it throws a TypeError exception)
* revise flushing:
- add an explicit flush call before fetching outcoming result
- for an in memory XML::Writer:
* add a boolean parameter to empty (or not) internal buffer
* return current internal buffer as string (with encoding associated to the document propagated for ruby >= 1.9 to the last one)
- for the others cases, just return the number of written bytes
* the most important: passing nil as value for arguments named pe result in undefined behavior (may segfault?). So, I change this default value (Qnil) by an internal one: Qundef