On Fri, Apr 26, 2013 at 2:23 PM, Steve the Fiddle <stevethefiddle@gmail.com> wrote:

The "Ctrl++" default is a bit weird - because there is no "+" key,
this is in effect a "dummy" binding (does nothing), but to allow for
users changing the defaults it must still bind to the actual Zoom In
function. If a user changes this key binding, then there is no way
they can change it back to Ctrl++ other than by resetting it to its
default (it is not possible to type Ctrl++ due to the absence of a "+"

Hi Steve,
I haven't tried this patch, but using audacity on windows, there isn't a problem with assigning the shortcut ctrl++ to a command.
The shortcuts in audacity use key codes, See for eg:
These aren't necessarily the same as the label on the key. So on an english keyboard, if you press the = key you get the key code for plus, and on a danish keyboard if you press the + key, then you get the same key code.
So on windows, using audacity, I can set up a shortcut for ctrl++ which works using either an english or danish keyboard.
I presume from you post, that there isn't the same nice behaviour on linux.