Don’t copy the already-cascaded style when copying nodes

Fix #1370.

weasyprint/svg/__init__.py

@@ -91,18 +91,14 @@ def __init__(self, wrapper, style):
         self._etree_node = wrapper.etree_element
         self._style = style
 
-        self.attrib = wrapper.etree_element.attrib
+        self.attrib = wrapper.etree_element.attrib.copy()
 
         self.vertices = []
         self.bounding_box = None
 
     def copy(self):
-        """Create a deep copy of the node."""
-        copy = Node(self._wrapper, self._style)
-        copy.attrib = self.attrib.copy()
-        copy.vertices = self.vertices.copy()
-        copy.bounding_box = None
-        return copy
+        """Create a deep copy of the node as it was when first created."""
+        return Node(self._wrapper, self._style)
 
     def get(self, key, default=None):
         """Get attribute."""

weasyprint/svg/defs.py

@@ -27,7 +27,7 @@ def use(svg, node, font_size):
 
     parsed_url = parse_url(node.get_href())
     if parsed_url.fragment and not parsed_url.path:
-        tree = svg.tree.get_child(parsed_url.fragment)
+        tree = svg.tree.get_child(parsed_url.fragment).copy()
     else:
         url = parsed_url.geturl()
         try:
@@ -39,7 +39,6 @@ def use(svg, node, font_size):
         else:
             use_svg.get_intrinsic_size(font_size)
             tree = use_svg.tree
-    tree = tree.copy()
 
     if tree.tag in ('svg', 'symbol'):
         # Explicitely specified