MIGRATE: test more corner cases.
MIGRATE: test more corner cases.

ramonsnir/redis,splitice/redis,slfs007/mk-redis,maodeyi/redis_lua,ramonsnir/redis,maodeyi/redis_lua,ramonsnir/redis,splitice/redis,splitice/redis,splitice/redis,maodeyi/redis_lua,louisliangjun/redis,louisliangjun/redis,louisliangjun/redis,louisliangjun/redis,slfs007/mk-redis,slfs007/mk-redis