Panic when WHERE clause contains IN [ NULL ]

create index ix5 on default(x1);

explain select x1 from default where x1 IN [NULL];

ithub.com/couchbase/query/server.(*Server).serviceRequest.func1()

/Users/sitaram/queryg/src/github.com/couchbase/query/server/server.go:451 +0xbc

panic(0x4868ba0, 0xc4200100c0)

/usr/local/Cellar/go/1.7.4_1/libexec/src/runtime/panic.go:458 +0x243

github.com/couchbase/query/planner.SargFor(0x4f00ba0, 0xc420138dc0, 0xc4206a1190, 0x1, 0x1, 0x1, 0x1, 0xc4207669e0, 0x40066b3, 0xc42075a758, ...)

/Users/sitaram/queryg/src/github.com/couchbase/query/planner/sarg.go:68 +0x35b

github.com/couchbase/query/planner.sargIndexes(0xc4207c9e90, 0x4f00ba0, 0xc420138dc0, 0xc42075aa68, 0xc4207c9e90, 0x0)

/Users/sitaram/queryg/src/github.com/couchbase/query/planner/build_scan_secondary.go:269 +0xea

github.com/couchbase/query/planner.(*builder).buildCoveringScan(0xc4201b2900, 0xc4207fe6c0, 0xc4208328a0, 0x4efff60, 0xc420138c80, 0x4f00ba0, 0xc420138dc0, 0x0, 0x0, 0x0, ...)

/Users/sitaram/queryg/src/github.com/couchbase/query/planner/build_scan_covering.go:49 +0x1865

github.com/couchbase/query/planner.(*builder).buildSecondaryScan(0xc4201b2900, 0xc4207fe6c0, 0xc4208328a0, 0x4efff60, 0xc420138c80, 0x4f00ba0, 0xc420138dc0, 0x0, 0x0, 0x1, ...)

/Users/sitaram/queryg/src/github.com/couchbase/query/planner/build_scan_secondary.go:41 +0x88e

github.com/couchbase/query/planner.(*builder).buildTermScan(0xc4201b2900, 0xc4208328a0, 0x4efff60, 0xc420138c80, 0x4f00ba0, 0xc420138dc0, 0x0, 0x0, 0xc42073b000, 0x3, ...)

/Users/sitaram/queryg/src/github.com/couchbase/query/planner/build_scan.go:186 +0x6ef

github.com/couchbase/query/planner.(*builder).buildSubsetScan(0xc4201b2900, 0x4ef5040, 0xc4207191d0, 0xc4208328a0, 0x4efff60, 0xc420138c80, 0x4f00ba0, 0xc420138dc0, 0x0, 0x0, …)