Field A is a value controller.
Field A has Value 1 that doesn't control any values.
You try to delete Value 1, and Bugzilla will throw an error that you can't delete it, because it controls (empty list of values).
This proves that either people don't use value controllers much, or that they don't delete field values very often. (More likely the latter.) The reason I say this is that this bug has been around for pretty much as long as we've had value controllers, and nobody's reported it.
Created attachment 456138 [details] [diff] [review]
Okay, this applies to HEAD at least. I'm not sure if it will also apply to 3.6--I forget when I split things out into ChoiceInterface.
Comment on attachment 456138 [details] [diff] [review]
Bugzilla/Field/ChoiceInterface.pm doesn't exist in 3.6.1.
Created attachment 459398 [details] [diff] [review]
Okay, I haven't tested this (I have to go to sleep right now, and setting up a testing environment was taking too long) but it compiles and it's basically just a straightforward backport. All I did was copy identical code into the right place.
Comment on attachment 459398 [details] [diff] [review]
Works fine. r=LpSolit
Committing to: bzr+ssh://bzr.mozilla.org/bugzilla/trunk/
Committed revision 7396.
Committing to: bzr+ssh://bzr.mozilla.org/bugzilla/4.0/
Committed revision 7340.
Committing to: bzr+ssh://bzr.mozilla.org/bugzilla/3.6/
Committed revision 7143.