Bash autocomplete on symlink to directory complete to whole directory, including slash

Enable the mark-symlinked-directories option for readline.

1. Edit ~/.inputrc:

   $include /etc/inputrc
   set mark-symlinked-directories on
   

2. Press C-x, C-r to reload the settings.

See section READLINE in the manual page of bash for further documentation.

For those who do not wish to add another dot file, you can also add this line to your ~/.bashrc:

bind 'set mark-symlinked-directories on'

I don't know if you can do it exactly as you've described, but if you hit tab twice, it should complete the exapansion.