This commit fixes two problems:
1. Doctypes introducing too many newlines
2. Elements with siblings and a common parent not being closed properly
== Doctypes
When generating the XML for a doctype the XML::Generator class would
append a trailing newline. This however meant that if the next text node
was also a newline you'd now have two newlines. In previous versions of
Oga this worked because the old XML generation code would call
String#strip on the XML to add after the doctype.
To support this in the new version we perform a lookahead in
XML::Generator#on_doctype to remove any trailing newlines added by this
method in case the first child node is a newline text node.
== Closing Elements
When an element has a sibling following it _and_ does not have any child
nodes it would not be closed properly when generating XML. This is due
to the "until next_node = ..." expression evaluating to true, thus never
executing its body.
There's probably some way to work around this by using the "loop"
method, but considering it's 02:09 I think the current approach is good
enough. Future me will probably hate me for it.
Yorick Peterse
e0e0687dc2