Bug 371454

Steps:
- Use a profile with "Start in same directory as current tab" enabled
- In one tab, run
  $ mkdir a
  $ cd a
  $ rmdir ../a
- Try to open a new tab

Expected:
Tab opens with some fallback cwd

Actual:
"""
Warning: Could not start program '/bin/bash' with arguments '/bin/bash'.
Warning: chdir: No such file or directory
"""
Cannot use the new tab.

I think I observed a hard hang of Konsole 16.08.1 but my packages had already been updated to 16.08.2 when I tried to repro and I didn't feel like downgrading to test again.