"Backspace" can be used to directory navigation, but it is unreliable and unpredictable due to how focus works. Nine examples:

A)
Steps to reproduce:
      Launch gedit and click on "Open".
      On the sidebar, go to the Home folder.
      Click on "Backspace"

Actual Results:
      It has no effect, there is a sound notification. (The location entry is focused and empty.)

B)
Steps to reproduce:
      Launch gedit and click on "Open".
      On the sidebar, go to "Documents" folder.
      Click on "Backspace"

Actual Results:
      It has no effect, there is a sound notification. (The location entry is focused and empty.)

C)
Steps to reproduce:
      Launch gedit and click on "Open".
      On the sidebar, click on Home folder.
      On the main list, double click on "Documents".
      Click on "Backspace"

Actual Results:
      It has no effect, there is a sound notification. (The location entry is focused and empty.)

D)
Steps to reproduce:
      Launch gedit and click on "Open".
      On the sidebar, click on "Documents" folder
      On the main list, double click on a subfolder.
      Click on "Backspace"

Actual Results:
      It takes me to parent folder, which is "Documents" in this case. (The location is unfocused.)

E)
Steps to reproduce:
      Launch gedit and click on "Open".
      On the sidebar, click on "Documents" folder.
      On the main list, double click on a subfolder.
      Click on "Backspace"
      Click on "Backspace" again.

Actual Results:
      The first "Backspace" takes me to parent folder, which is "Documents" in this case. (The location, which was unfocused, gets focus.) The second "Backspace" has no effect, there is a sound notification. (The location entry is focused and empty.)

F)
Steps to reproduce:
      Launch gedit and click on "Save".
      On the sidebar, click on the Home folder.
      Click on "Backspace"

Actual Results:
      It has no effect. There is no sound notification. (The filename entry is unfocused.)

G)
Steps to reproduce:
      Launch gedit and click on "Save".
      On the sidebar, click on "Documents" folder.
      Click on "Backspace"

Actual Results:
      "Documents" is removed from sidebar. ("Oh no... what happened to my documents?")

H)
Steps to reproduce:
      Launch gedit and click on "Save".
      On the sidebar, click on "Documents" folder.
      On the main list, double click on a subfolder.
      Click on "Backspace"

Actual Results:
      It takes me to parent folder, which is "Documents" in this case. (The filename entry is not focused)

I)
Steps to reproduce:
      Launch gedit and click on "Save".
      On the sidebar, click on "Documents" folder.
      On the main list, double click on a subfolder.
      Click on "Backspace"
      Click on "Backspace" again.

Actual Results:
      The first "Backspace" takes me to parent folder, which is "Documents" in this case. The second "Backspace" takes me to parent folder, which is the Home folder in this case. (The filename entry is not focused.)


Expected result for all of above:
      Ideally, the same result in all cases, whichever that would be. At minimum, a predictable pattern.
      In particular,
      - C) and D) should really be the same;
      - E) and I) should be the same;
      - if A) and B) are the same, then F) and G) should be the same as well.

Tested with gtk+ version 3.6.4 from Fedora 18.