return explicit null if there is no root

diff --git a/src/doc.js b/src/doc.js
index 843ff0351a06d33c2251a4171fbb227e42dd030f..d4bf7e59368a26b3dbcdc8ee0d014619da1526e9 100644 (file)
--- a/src/doc.js
+++ b/src/doc.js
@@ -23,7 +23,9 @@ SVG.Doc = SVG.invent({
         if(parent.isRoot()) return parent
       }
 
-      throw new Error('This should never be reached')
+      // this can only happen when you have something like
+      // <g><svg>...</svg></g>
+      return null
     },
     // Add namespaces
     namespace: function() {