Let's say I want to open a project 'foobar' in gnome-builder.  The project is in ~/src.  I get a file chooser and start typing 'src'.   I expect that if I'll be able to press Enter (or maybe /) and then start typing 'foo'.

This doesn't work: if I press Enter, nothing happens.  I have to explicitly focus the file list (by pressing Down) before Enter opens the folder.

Now I type 'foo' (i.e. a sufficiently unique prefix of 'foobar'), which again matches the thing I want, and then I have to press Down again and Enter to select it.

If I try the other alternative I considered -- src/foo -- it just clears the result list as soon as I type the /.