fix_svg_for_rsvg_pandoc.py

from lxml.etree import fromstring, tostring


def hatch_safe_svg(data):
    # rsvg-convert doesn't resolve <pattern> fills from #fragment
    # URIs if they occur downfile from the usage. This makes sure 
    # definitions come first.
    doc = fromstring(data)
    defs = [el for el in doc.getchildren() 
            if el.tag == "{http://www.w3.org/2000/svg}defs"]
    for defn in defs:
        doc.remove(defn)
        doc.insert(0, defn)
    return tostring(doc)