redisDisconnectCallback is not called while disconnecting asynchronous connection to redis

[zh1029]

hiredis version: V1.1-0.

Uses redisAsyncConnectWithOptions() function with option has REDIS_OPT_PREFER_IPV4 as below code for example.

_struct event_base *base = event_base_new();
redisOptions options = {0};
REDIS_OPTIONS_SET_TCP(&options, "127.0.0.1", 6379);
struct timeval tv = {0};
tv.tv_sec = 1;
options.connect_timeout = &tv;
opt.options |= REDIS_OPT_PREFER_IPV4;

redisAsyncContext *c = redisAsyncConnectWithOptions(&options);
if (c->err) {
    /* Let *c leak for now... */
    printf("Error: %s\n", c->errstr);
    return 1;
}

redisLibeventAttach(c,base);
redisAsyncSetConnectCallback(c,connectCallback);
redisAsyncSetDisconnectCallback(c,disconnectCallback);
redisAsyncCommand(c, NULL, NULL, "SET key %b", argv[argc-1], strlen(argv[argc-1]));
redisAsyncCommand(c, getCallback, (char*)"end-1", "GET key");_

It lead to no calling disconnectCallback while the asynchronous connection disconnecting happened.
It is a bug in hiredis due to duplicated constants value between REDIS_OPT_PREFER_IPV4 and REDIS_OPT_NOAUTOFREE as below definition in hiredis.h

#define REDIS_OPT_PREFER_IPV4 0x04
#define REDIS_OPT_NOAUTOFREE 0x04

It cause logical error in redisConnectWithOptions() that mistaking set the context flag REDIS_NO_AUTO_FREE which is not as expected.

redisContext *redisConnectWithOptions(const redisOptions *options) {
redisContext *c = redisContextInit();
if (c == NULL) {
return NULL;
}
if (!(options->options & REDIS_OPT_NONBLOCK)) {
c->flags |= REDIS_BLOCK;
}
if (options->options & REDIS_OPT_REUSEADDR) {
c->flags |= REDIS_REUSEADDR;
}
if (options->options & REDIS_OPT_NOAUTOFREE) {
c->flags |= REDIS_NO_AUTO_FREE;
}
if (options->options & REDIS_OPT_NOAUTOFREEREPLIES) {
c->flags |= REDIS_NO_AUTO_FREE_REPLIES;
}
if (options->options & REDIS_OPT_PREFER_IPV4) {
c->flags |= REDIS_PREFER_IPV4;
}
if (options->options & REDIS_OPT_PREFER_IPV6) {
c->flags |= REDIS_PREFER_IPV6;
}

And eventually below __redisAsyncFree() is not invoked.

_/* Helper function to make the disconnect happen and clean up. */
void __redisAsyncDisconnect(redisAsyncContext ac) {
......
/ For non-clean disconnects, __redisAsyncFree() will execute pending
* callbacks with a NULL-reply. */
if (!(c->flags & REDIS_NO_AUTO_FREE)) {
_redisAsyncFree(ac);
}
......
}

Same duplicated constants value need to fix as well:
#define REDIS_OPT_PREFER_IPV6 0x08
#define REDIS_OPT_NO_PUSH_AUTOFREE 0x08