Currently, CompositeShadowTreeWalker uses InsertionPoint::isActive() to judge whether there are distributed nodes into the insertion point.
But that is wrong. That should use InsertionPoint::hasDistribution() since InsertionPoint::isActive() return true when the insertion point which does not select any node and has fallback elements.
WONTFIX. CompositeShadowTreeWalker is innocent.
Reopened. ComposedShadowTreeWalker wrongly traverses nodes in the following case:
If ComposendShadowTreeWalker traverses this tree, starting with #fallback element, it wrongly *escapes* out of the parent <content> element. Since a #fallback element is not used in composed shadow dom tree, it should be treated as orphaned subtree.
Created attachment 147789 [details]
Comment on attachment 147789 [details]
Clearing flags on attachment: 147789
Committed r121481: <http://trac.webkit.org/changeset/121481>
All reviewed patches have been landed. Closing bug.