Spans Includes self reference from same keyspace of UNNEST

create index ix1 on default(c1);

EXPLAIN SELECT 1 FROM default AS d UNNEST d.a1 AS a  WHERE d.c1 != 10 AND d.c1 = a.u1;

    "spans": [

                        {

                            "range": [

                                {

                                    "high": "(`a`.`u1`)",

                                    "inclusion": 3,

                                    "low": "(`a`.`u1`)"

                                }

                            ]

                        }

                    ],

_time=2020-02-27T14:23:36.446-08:00 _level=SEVERE _msg=panic: runtime error: invalid memory address or nil pointer dereference

_time=2020-02-27T14:23:36.446-08:00 _level=SEVERE _msg=request text: <ud>SELECT 1 FROM default AS d UNNEST d.a1 AS a  WHERE d.c1 != 10 AND d.c1 = a.u1;</ud>

_time=2020-02-27T14:23:36.446-08:00 _level=SEVERE _msg=stack: goroutine 4424 [running]:

github.com/couchbase/query/execution.(*Context).Recover(0xc0000bf6c0, 0x0)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/context.go:653 +0xbb

panic(0x5210440, 0x66c6640)

	/usr/local/Cellar/go/1.13.7/libexec/src/runtime/panic.go:679 +0x1b2

github.com/couchbase/query/expression.(*Identifier).Evaluate(0xc00176a480, 0x0, 0x0, 0x5727b40, 0xc0000bf6c0, 0xc000f46000, 0x8, 0x1, 0xf)

	/Users/sitaram/master/query/src/github.com/couchbase/query/expression/identifier.go:64 +0x22

github.com/couchbase/query/expression.(*BinaryFunctionBase).BinaryEval(0xc000a45720, 0x56f9860, 0xc000a45720, 0x0, 0x0, 0x5727b40, 0xc0000bf6c0, 0x7d7d30313231, 0x20, 0x28, ...)

	/Users/sitaram/master/query/src/github.com/couchbase/query/expression/function.go:395 +0xbf

github.com/couchbase/query/expression.(*Field).Evaluate(0xc000a45720, 0x0, 0x0, 0x5727b40, 0xc0000bf6c0, 0x2243505247737466, 0x66222c303331393a, 0xc000f71bf0, 0x400e6f8)

	/Users/sitaram/master/query/src/github.com/couchbase/query/expression/nav_field.go:52 +0x70

github.com/couchbase/query/execution.evalOne(0x575f420, 0xc000a45720, 0xc0000bf6c0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x69222c3530313900)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/scan_util.go:21 +0x1ce

github.com/couchbase/query/execution.evalSpan2(0xc00182cea0, 0x1, 0x2, 0x0, 0x0, 0xc0000bf6c0, 0x6464222c22363962, 0x75227b3a2273636f, 0x6f702f223a226972, 0x616665642f736c6f, ...)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/scan_index2.go:200 +0x115

github.com/couchbase/query/execution.evalSpan3(0xc00182cea0, 0x1, 0x2, 0x0, 0x0, 0x0, 0xc0000bf6c0, 0xc001cc8ba0, 0x1, 0xc000930ec8, ...)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/scan_index3.go:234 +0x944

github.com/couchbase/query/execution.(*IndexScan3).scan(0xc000bff680, 0xc0000bf6c0, 0xc000fb8900, 0x0, 0x0)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/scan_index3.go:156 +0xf9

created by github.com/couchbase/query/execution.(*IndexScan3).RunOnce.func1

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/scan_index3.go:68 +0x2ff

goroutine 4424 [running]:

github.com/couchbase/query/execution.(*Context).Recover(0xc0000bf6c0, 0x0)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/context.go:653 +0xbb

panic(0x5210440, 0x66c6640)

	/usr/local/Cellar/go/1.13.7/libexec/src/runtime/panic.go:679 +0x1b2

github.com/couchbase/query/expression.(*Identifier).Evaluate(0xc00176a480, 0x0, 0x0, 0x5727b40, 0xc0000bf6c0, 0xc000f46000, 0x8, 0x1, 0xf)

	/Users/sitaram/master/query/src/github.com/couchbase/query/expression/identifier.go:64 +0x22

github.com/couchbase/query/expression.(*BinaryFunctionBase).BinaryEval(0xc000a45720, 0x56f9860, 0xc000a45720, 0x0, 0x0, 0x5727b40, 0xc0000bf6c0, 0x7d7d30313231, 0x20, 0x28, ...)

	/Users/sitaram/master/query/src/github.com/couchbase/query/expression/function.go:395 +0xbf

github.com/couchbase/query/expression.(*Field).Evaluate(0xc000a45720, 0x0, 0x0, 0x5727b40, 0xc0000bf6c0, 0x2243505247737466, 0x66222c303331393a, 0xc000f71bf0, 0x400e6f8)

	/Users/sitaram/master/query/src/github.com/couchbase/query/expression/nav_field.go:52 +0x70

github.com/couchbase/query/execution.evalOne(0x575f420, 0xc000a45720, 0xc0000bf6c0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x69222c3530313900)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/scan_util.go:21 +0x1ce

github.com/couchbase/query/execution.evalSpan2(0xc00182cea0, 0x1, 0x2, 0x0, 0x0, 0xc0000bf6c0, 0x6464222c22363962, 0x75227b3a2273636f, 0x6f702f223a226972, 0x616665642f736c6f, ...)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/scan_index2.go:200 +0x115

github.com/couchbase/query/execution.evalSpan3(0xc00182cea0, 0x1, 0x2, 0x0, 0x0, 0x0, 0xc0000bf6c0, 0xc001cc8ba0, 0x1, 0xc000930ec8, ...)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/scan_index3.go:234 +0x944

github.com/couchbase/query/execution.(*IndexScan3).scan(0xc000bff680, 0xc0000bf6c0, 0xc000fb8900, 0x0, 0x0)

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/scan_index3.go:156 +0xf9

created by github.com/couchbase/query/execution.(*IndexScan3).RunOnce.func1

	/Users/sitaram/master/query/src/github.com/couchbase/query/execution/scan_index3.go:68 +0x2ff