Nested YANG choice does not work

[olofhagsand]

Choice within choice does not work as expected, ie in the below yang, if topA is first configured, and then something in topB, the topA config remains, but should not:
cli example:

olof@alarik /> show configuration 
clixon-example:c {
    A1x ff;
    Ay foo;
}         
olof@alarik /> set c B1x ff            
olof@alarik /> show configuration 
clixon-example:c {
    B1x ff;
    Ay foo;  <---------- Should be removed
}

yang:

    container c {
	choice top{
	    case topA {
		choice A{
		    leaf A1x{
			type string;
		    }
		    leaf A2x{
			type string;
		    }
		}
		leaf Ay{
		    type string;
		}
	    }
	    case topB{
		choice B{
		    case B1{
			leaf B1x{
			    type string;
			}
		    }
		    case B2{
			leaf B2x{
			    type string;
			}
		    }
		}
		leaf By{
		    type string;
		}
	    }
	}
    }

Thanks: @mgsmith1000