When sorting tree columns in bookmarks, I get: ###!!! ASSERTION: Parent content should not be NULL!: 'Error', file /home/bryner/Source/mozilla/layout/xul/base/src/nsXULTreeOuterGroupFrame.cpp, line 761 I believe this is a result of the "sort - remove treechildren - insert treechildren" sequence interacting with the current item updating code in nsXULElement::RemoveChildAt. We had a similar problem in XULTemplateBuilder that was resolved by removing the treechildren before doing any insertions or removals (thus making the tree aware that it had no rows). However, applying this same logic to XULSortService::DoSort appears to make sorting nonfunctional. This was split off from bug 52789, see that bug for further details.
Old bug, closing.
tever is not RDF QA anymore