Arithmetic operations on unnest on array of values causes panic

insert into default values ("k02",{"id":123,"a":[123,234]});

select d.id-a from default d use keys ["k02"] unnest d.a as a;

select d.id+a from default d use keys ["k02"] unnest d.a as a;

github.com/couchbase/query/execution.(*Context).Recover(0xc4201dfc20)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/context.go:455 +0xbc

panic(0x4914500, 0xc4207a5d80)

	/usr/local/Cellar/go/1.8/libexec/src/runtime/panic.go:489 +0x2cf

github.com/couchbase/query/expression.(*Sub).Apply(0xc42050bc70, 0x5020840, 0xc4201dfc20, 0x5050e00, 0xc420759a50, 0x50503e0, 0xc420a19920, 0x0, 0x0, 0x8, ...)

	/Users/sitaram/master/query/src/github.com/couchbase/query/expression/arith_sub.go:56 +0x1a9

github.com/couchbase/query/expression.(*BinaryFunctionBase).BinaryEval(0xc42050bc70, 0x5017900, 0xc42050bc70, 0x50503e0, 0xc420a198f0, 0x5020840, 0xc4201dfc20, 0x49ceee0, 0x4a1cb40, 0x4a42900, ...)

	/Users/sitaram/master/query/src/github.com/couchbase/query/expression/function.go:396 +0x18c

github.com/couchbase/query/expression.(*Sub).Evaluate(0xc42050bc70, 0x50503e0, 0xc420a198f0, 0x5020840, 0xc4201dfc20, 0x0, 0xc420f3ba40, 0x0, 0xc4206ee2d0)

	/Users/sitaram/master/query/src/github.com/couchbase/query/expression/arith_sub.go:44 +0x70

github.com/couchbase/query/execution.(*InitialProject).processTerms(0xc42088ac00, 0x50536e0, 0xc420a198f0, 0xc4201dfc20, 0x4086512)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/project_initial.go:107 +0x315

github.com/couchbase/query/execution.(*InitialProject).processItem(0xc42088ac00, 0x50536e0, 0xc420a198f0, 0xc4201dfc20, 0x1)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/project_initial.go:92 +0x42c

github.com/couchbase/query/execution.(*base).runConsumer.func1()

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/base.go:269 +0x3a6

sync.(*Once).Do(0xc42088ac50, 0xc42055c738)

	/usr/local/Cellar/go/1.8/libexec/src/sync/once.go:44 +0xbe

github.com/couchbase/query/execution.(*base).runConsumer(0xc42088ac00, 0x5022ec0, 0xc42088ac00, 0xc4201dfc20, 0x0, 0x0)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/base.go:280 +0xad

github.com/couchbase/query/execution.(*InitialProject).RunOnce(0xc42088ac00, 0xc4201dfc20, 0x0, 0x0)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/project_initial.go:45 +0x5c

created by github.com/couchbase/query/execution.(*base).runConsumer.func1

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/base.go:245 +0x487