Redis SPOP returns an empty bulk instead of nil

When used with the optional COUNT argument on a non-existing key. This goes against the expected behavior, isn't consistent with the rest of the API and defies the documentation :)

Comment From: itamarhaber

@antirez - what say you? Keep the current behavior (and document it) or apply the fix (and document it)?

Comment From: yangbodong22011

@itamarhaber @antirez Hello, I think this problem needs to be discussed again. In unstable branch, SPOP returns nil instead of an empty bulk, this will result in incompatibility with versions 5.0 and earlier.

unstable：https://github.com/antirez/redis/blob/unstable/src/t_set.c#L418 5.0：https://github.com/antirez/redis/blob/5.0/src/t_set.c#L418

Comment From: yangbodong22011

@itamarhaber @antirez Please look at my question, thank you.

Comment From: yangbodong22011

@antirez @itamarhaber Please check my question in your free time, thanks.

Comment From: itamarhaber

Fixed via 8d9a6a2