tl;dr:
In the xml dumps, I want to change <text> <sha1> <model> <format> to <model> <format> <text> <sha1>
However, this is a breaking change to our XML schema. See https://bugzilla.wikimedia.org/show_bug.cgi?id=72417
Background:
While trying to fix bug 72361, I ran into an issue with our current XML dump format:
The <model> and <format> tags are placed *after* the <text> tag. This means that we don't know how to handle the text when we process XML events in a stream - we'd have to buffer the text, wait until we know model and format, and then process it. A pain.
The current order has no deeper meaning - it is, indeed, my own fault: i didn't think this through when adding these tags. I propose to change the order of the tags now, to make stream processing easier.
That would technically be a breaking change to the dump format, incompatible with https://www.mediawiki.org/xml/export-0.8.xsd and export-0.9.xsd. I doubt however that any consumers rely on the current placement of <model> and <format>, as it is extremely inconvenient (compare bug 72361), but you never know.
I propose to release a new XSD version 0.10 with the order changed, and mention it in the release notes. Should be fine.
Any objections?
-- daniel