It's actually a bug from Firefox.
Rules apply to the defs rect
elements, but they don't apply when the use
tag clones the defs rect
.
Replacing the defs
with a g
tag shows that the defs rect
is filled; but the rules are not applied to the "-generated clone".
Correct behavior is Chrome's one, filling the use-generated clone; use-cloned version of the defs rect
is wrongly not filled by firefox.
See https://bugzilla.mozilla.org/show_bug.cgi?id=997362#c4 for more explanations.