bash: LD_ASSUME_KERNEL: unbound variable with set -u

[jweiss]

The following was reported by kenta on test.dialup which recently took the latest debathena-dotfiles patch

I have

set -u

in my .bashrc, and very recently (in the last two days?) I
have begun seeing a message

bash: LD_ASSUME_KERNEL: unbound variable

every time I start a bash shell (including when creating a
new "screen" in screen).

[jdreed]

Fix committed in r25647. Use -n "${LD_ASSUME_KERNEL+x}" instead of -n "$LD_ASSUME_KERNEL".

[jdreed]

Anders points out that we want to fix #1084 at the same time.

[jdreed]

I have tested this with two test accounts on different machines, and it works. The current dotfiles prevent you from logging in at all graphically if you 'set -u'. I'm going to move this to proposed tomorrow, and then production on Monday, unless someone objects.

[jweiss]

I've tested this and confirmed that it solves kenta's problem with "set -u"