fix potential uninitialized read
If callback was set before scheduleTimer was set (i..e before one of the
attach()) calls.
@@ -144,6 +144,7 @@ static redisAsyncContext *redisAsyncInitialize(redisContext *c) {
ac->ev.addWrite = NULL;
ac->ev.delWrite = NULL;
ac->ev.cleanup = NULL;
+ ac->ev.scheduleTimer = NULL;
ac->onConnect = NULL;
ac->onDisconnect = NULL;
