cf7497a created the issue

When you double-click on a file (to download it to a temporary file and open it up in an editor), but the file is already open in the editor, nothing happens. Until the last version, it used to be opened again in a second copy.

While it is nice to avoid multiple parallel versions of the same file, it took me several instances of this situation to realize what was happening, and to notice that that specific file was already open among a set of 20-30 open files in the project (all of which have barely distinguishable filenames, see #1101). I kept double-clicking, nothing happened, so I thought Cyberduck had got stuck or my connection had died or whatever.

I suggest that, at least, you should pop up an error message advising the user that the file is already open, or write something in the status bar at the bottom. (Bringing the file up in the editor window would be even better, but that might be more difficult.)

Thanks,