User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:41.0) Gecko/20100101 Firefox/41.0 Build ID: 2015091800 Steps to reproduce: http://hg.mozilla.org/mozilla-central/rev/f692ed55fb8a makes all Windows Common Dialogs children of a temporary window which is destroyed after the dialog is shown. For the print dialog, the parent window handle is retrieved by the nsPrintingPromptService::GetHWNDForDOMWindow() function. However, not all code paths in this function return a temporary window. From looking at the code, it seems that if Gecko is embedded, a non-temporary window, namely the result of site->GetSiteWindow(), will be returned. This window will be destroyed after showing the print dialog. In particular, this causes Wine's embedded IE, which uses Gecko, to freeze after calling the print dialog.
Created attachment 8695866 [details] [diff] [review] fix Good catch, thanks. The attached patch fixes it for me.