Created attachment 475341 [details] testcase Overview: The anchor-scope property traps the specified anchor-names from being exposed outside the element's subtree. But our implementation traps any anchor that happens to have a matching name, even if it has other names which are not trapped. Steps to Reproduce: 1. Create an anchor with two anchor names. 2. Wrap it in an anchor-scope that only has one of those names. 3. Try to attach an anchor outside this subtree to the unscoped name. Expected Result: Attachment works. Actual Result: Attachment does not work. Additional Information: See anchorScopeForAnchorElement() for the source of the problem.