Add unit test for #1793
Add unit test for #1793

AmeBel/atomspace,rTreutlein/atomspace,rTreutlein/atomspace,AmeBel/atomspace,rTreutlein/atomspace,rTreutlein/atomspace,rTreutlein/atomspace,AmeBel/atomspace,AmeBel/atomspace,AmeBel/atomspace