LPOS command sends FIRST instead of RANK

[christophstrobl]

LPosArgs uses FIRST instead of RANK causing a syntax error

"RPUSH" "mylist" "a" "b" "c" "1" "2" "3" "c" "c"
"LPOS" "mylist" "c" "COUNT" "2" "FIRST" "-1"
> ERR syntax error
"LPOS" "mylist" "c" "COUNT" "2" "RANK" "-1"
> [7,6]

Please rename LPosArgs.first to LPosArgs.rank and send the RANK option if present.

Commit redis/redis@a5a3a7b changed the option name.

[mp911de]

That's fixed now.