Comment 5 for bug 604000

<marker
       inkscape:stockid="Arrow2Lend"
       orient="auto"
       refY="0"
       refX="0"
       id="Arrow2Lend"
       style="overflow:visible">

-->

<marker id="b" refY="0" refX="0" orient="auto">

style="overflow:visible" was removed from the marker; restoring it allowed the arrows to show again.

The SVG specification says, for the overflow property,

> The initial value for ‘overflow’ as defined in [CSS2-overflow]
> is 'visible', and this applies also to the root ‘svg’ element;
> however, for child elements of an SVG document, SVG's user
> agent style sheet overrides this initial value and sets the
> ‘overflow’ property on elements that establish new viewports
> (e.g., ‘svg’ elements), ‘pattern’ elements and ‘marker’
> elements to the value 'hidden'.

Seeing as 'marker' gets the default value of 'overflow: hidden', the removal of default attribute values should not affect the 'overflow' property, or should be modified to be 'hidden' for elements other than <svg>.