Add non-const connect callback

README.md

@@ -459,6 +459,21 @@ aliased to `redisConnectCallback`:
 void(const redisAsyncContext *ac, int status);
 ```
 
+If `hiredis` >= v1.1.0 is used you can alternatively set the following
+connect callback which will be passed a non-const `redisAsyncContext*` on
+invocation (e.g. allowing to set a push callback).
+
+```c
+int redisClusterAsyncSetConnectCallbackNC(redisClusterAsyncContext *acc,
+                                          redisConnectCallbackNC *fn);
+```
+
+The callback function should have the following prototype,
+aliased to `redisConnectCallbackNC`:
+```c
+void(redisAsyncContext *ac, int status);
+```
+
 On a connection attempt, the `status` argument is set to `REDIS_OK`
 when the connection was successful.
 The file description of the connection socket can be retrieved

hircluster.c

@@ -3715,6 +3715,11 @@ redisAsyncContext *actx_get_by_node(redisClusterAsyncContext *acc,
     if (acc->onConnect) {
         redisAsyncSetConnectCallback(ac, acc->onConnect);
     }
+#ifndef HIRCLUSTER_NO_NONCONST_CONNECT_CB
+    else if (acc->onConnectNC) {
+        redisAsyncSetConnectCallbackNC(ac, acc->onConnectNC);
+    }
+#endif
 
     if (acc->onDisconnect) {
         redisAsyncSetDisconnectCallback(ac, acc->onDisconnect);
@@ -3775,12 +3780,26 @@ int redisClusterAsyncConnect2(redisClusterAsyncContext *acc) {
 
 int redisClusterAsyncSetConnectCallback(redisClusterAsyncContext *acc,
                                         redisConnectCallback *fn) {
-    if (acc->onConnect == NULL) {
-        acc->onConnect = fn;
-        return REDIS_OK;
+    if (acc->onConnect != NULL)
+        return REDIS_ERR;
+#ifndef HIRCLUSTER_NO_NONCONST_CONNECT_CB
+    if (acc->onConnectNC != NULL)
+        return REDIS_ERR;
+#endif
+    acc->onConnect = fn;
+    return REDIS_OK;
+}
+
+#ifndef HIRCLUSTER_NO_NONCONST_CONNECT_CB
+int redisClusterAsyncSetConnectCallbackNC(redisClusterAsyncContext *acc,
+                                          redisConnectCallbackNC *fn) {
+    if (acc->onConnectNC != NULL || acc->onConnect == NULL) {
+        return REDIS_ERR;
     }
-    return REDIS_ERR;
+    acc->onConnectNC = fn;
+    return REDIS_OK;
 }
+#endif
 
 int redisClusterAsyncSetDisconnectCallback(redisClusterAsyncContext *acc,
                                            redisDisconnectCallback *fn) {

hircluster.h

@@ -67,6 +67,11 @@
 #define HIRCLUSTER_EVENT_READY 2
 #define HIRCLUSTER_EVENT_FREE_CONTEXT 3
 
+/* The non-const connect callback is missing in hiredis API prior v.1.1.0 */
+#if !(HIREDIS_MAJOR >= 1 && HIREDIS_MINOR >= 1)
+#define HIRCLUSTER_NO_NONCONST_CONNECT_CB
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -159,6 +164,9 @@ typedef struct redisClusterAsyncContext {
 
     /* Called when the first write event was received. */
     redisConnectCallback *onConnect;
+#ifndef HIRCLUSTER_NO_NONCONST_CONNECT_CB
+    redisConnectCallbackNC *onConnectNC;
+#endif
 
 } redisClusterAsyncContext;
 
@@ -286,6 +294,10 @@ void redisClusterAsyncFree(redisClusterAsyncContext *acc);
 
 int redisClusterAsyncSetConnectCallback(redisClusterAsyncContext *acc,
                                         redisConnectCallback *fn);
+#ifndef HIRCLUSTER_NO_NONCONST_CONNECT_CB
+int redisClusterAsyncSetConnectCallbackNC(redisClusterAsyncContext *acc,
+                                          redisConnectCallbackNC *fn);
+#endif
 int redisClusterAsyncSetDisconnectCallback(redisClusterAsyncContext *acc,
                                            redisDisconnectCallback *fn);