Steps to reproduce - Create a new document - Use File -> Export as PDF - Close the dialog by using the Cancel button or the Close button on the window bar - Result : a Filesave dialog appears Needs to be checked on 3.5
Good news, not present in 3.5, seems to be linked to this commit also : http://cgit.freedesktop.org/libreoffice/core/commit/?id=5d846ebeb55b1e295fb53f473f0fb2b88712e001
good thing this change is a master-only change :-). Its a pain, but finding and fixing these weird-ass cancel buttons makes it possible to refactor our dialogs.
http://cgit.freedesktop.org/libreoffice/core/commit/?id=cdd597746ff43c02ae613304ffe7456ec855181f