segfault on add_child_node when GC enabled

[canadaduane]

The following code snippet will (almost always) cause a segfault after calling add_child_node when ruby garbage collection is enabled:

https://gist.github.com/7602296

I've tested this on Nokogiri 1.6.0 using libxml2 2.8.0 and 2.9.1. Disabling GC prevents the segfault from occurring.

I'd like to isolate the issue further, but I'm not sure where to dig in next. Any ideas on how to approach this?

[canadaduane]

Once in a while, instead of a segfault, ruby throws an exception:

/Users/duane/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/nokogiri-1.6.0/lib/nokogiri/xml/node.rb:949:in `add_child_node': node must be a Nokogiri::XML::Node (ArgumentError)
    from /Users/duane/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/nokogiri-1.6.0/lib/nokogiri/xml/node.rb:949:in `add_child_node_and_reparent_attrs'
    from /Users/duane/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/nokogiri-1.6.0/lib/nokogiri/xml/node.rb:273:in `block in add_child'
    from /Users/duane/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/nokogiri-1.6.0/lib/nokogiri/xml/node_set.rb:237:in `block in each'
    from /Users/duane/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/nokogiri-1.6.0/lib/nokogiri/xml/node_set.rb:236:in `upto'
    from /Users/duane/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/nokogiri-1.6.0/lib/nokogiri/xml/node_set.rb:236:in `each'
    from /Users/duane/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/nokogiri-1.6.0/lib/nokogiri/xml/node.rb:273:in `add_child'
    from /Users/duane/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/nokogiri-1.6.0/lib/nokogiri/xml/node.rb:288:in `<<'

When I inspect the value of the object that must be a Nokogiri::XML::Node and that is throwing the ArgumentError, I get a large integer such as "-2882299370178845946". The integer value is different each time.

[canadaduane]

I currently think this is a Representable-specific issue, so I'm closing the ticket.