This was fixed in mac port in r180094, but I don't know which previous revision introduced the regression. It can be reproduced with /webkit2/WebKitWebView/populate-menu but we didn't notice it because the TestContextMenu test is still skipped in the bots :-/ This also affects to 2.8 branch.
Created attachment 258274 [details]
Comment on attachment 258274 [details]
View in context: https://bugs.webkit.org/attachment.cgi?id=258274&action=review
> + for (auto iter = m_signalHandlers.begin(); iter != m_signalHandlers.end(); ++iter)
for (auto handler : m_signalHandlers)
Committed r188031: <http://trac.webkit.org/changeset/188031>