On Ubunto 19.04 with Geany 1.34.1, if I select multiple files in Nautilus and select "Open with Geany" from the context menu, each file opens a new instance of Geany instead of all files opening in the existing Geany window. I don't see anything in the Preferences to control this behavior. I would always want all files to open in the current window and would expect this to be the default behavior