Fix RedisReply leaving connection in unusable state if an exception o…

[machindertech]

…ccurs during initialization

This is required because if an exception is thrown in a constructor, the
destructor will not be called.

[s-ludwig]

AFAICS, drop() would only do something if reading a multi-reply failed. But the only way that could throw an exception is if the count is not a valid long string. But then then the reply length would still stay 0 and drop still wouldn't do anything.

I think the correct thing to do would be to instead close the connection, but only for the two cases of "unknown reply" and an invalid multi-reply length string. What do you think?

[machindertech]

The issue we were having was that when an exception is thrown, the ctx.refCount stays incremented and then the next RedisReply fails on the assert(ctx.refCount == 0). Any kind of exception in initialize() will cause the assert to be triggered for the next reply.

[s-ludwig]

Can you try the issue1412_redis_reply_exception branch? I've more or less implemented the approach outlined above there.

[machindertech]

The issue1412_redis_reply_exception branch seems to fix the issues that we were having, so we're closing this pull request.