login impossible because lightdm-session crashes

[Lorenz]

If there is a bash script (with bash commands) in /etc/profile.d lightdm-session crashes and the login screen is displayed again.

The problem is that standard shell is dash and sh is linked to dash.
One solution for avoiding this is to change the shebang to #!/bin/bash.
But this may crash with other shells.

Installed versions:
lightdm 1.9.12-0ubunu1
lightdm-kde-greeter 0.3.2.2-0ubuntu1

And script to reproduce the crash (/etc/profile.d/crash.sh):
#!/bin/bash
a=("foo" "bar")
echo ${a[@]}