only check embroiderable tags for pattern marker

lib/elements/pattern.py

@@ -6,6 +6,7 @@
 import inkex
 
 from ..i18n import _
+from ..svg.tags import EMBROIDERABLE_TAGS
 from .element import EmbroideryElement
 from .validation import ObjectTypeWarning
 
@@ -33,4 +34,6 @@ class PatternObject(EmbroideryElement):
 
 
 def is_pattern(node):
+    if node.tag not in EMBROIDERABLE_TAGS:
+        return False
     return "marker-start:url(#inkstitch-pattern-marker)" in node.get('style', '')