Wt

Clicking on the "+" expand icon for a directory that is not already selected will visibly expand the directory, then collapse it. A second attempt to expand will succeed because the directory will have become selected from the prior attempt. This issue is present on github master 4.0.0-0-gf36f334d. At present, the behavior can be observed on the webtoolkit.eu site, e.g. at wt/src/hangman.

I believe this issue was introduced with changes to WAbstractItemView.C and WTreeView.C in commit fd45eb4b. However, the problem seems to be related to assumptions made in the example source viewer.

Attached, for your review, is a patch to the example that seems to help (based on limited testing).