slice == nil comparison

[DQNEO]

Currently in some cases slice == nil gives false even if slice is nil.

Expected results

when slice is nil,

expression	value
slice == nil	true
nil == slice	true
slice =! nil	false
nil != slice	false

when slice is non-nil,

expression	value
slice == nil	false
nil == slice	false
slice =! nil	true
nil != slice	true

[DQNEO]

This case works accidentally :)