Setup/cleanup (struct msg)->msg_info correctly

Without proper cleanup, we risk leaking memory and having multiple
owners overwriting the same memory.

src/dyn_message.c

@@ -421,6 +421,20 @@ static struct msg *_msg_get(struct conn *conn, bool request,
   msg->additional_each_rspmgrs = NULL;
   msg->rspmgrs_inited = false;
 
+  // Init the write_with_ts struct:
+  struct write_with_ts *minfo = &msg->msg_info;
+  minfo->add_set = NULL;
+  minfo->rem_set = NULL;
+  minfo->keys = NULL;
+  minfo->num_keys = 0;
+  minfo->fields = NULL;
+  minfo->num_fields = 0;
+  minfo->values = NULL;
+  minfo->num_values = 0;
+  minfo->optionals = NULL;
+  minfo->num_optionals = 0;
+  minfo->rewrite_script = NULL;
+  minfo->total_num_tokens = 0;
   return msg;
 }
 
@@ -647,6 +661,19 @@ void msg_put(struct msg *msg) {
     msg->orig_msg = NULL;
   }
 
+  if (msg->msg_info.keys) {
+    array_destroy(msg->msg_info.keys);
+  }
+  if (msg->msg_info.fields) {
+    array_destroy(msg->msg_info.fields);
+  }
+  if (msg->msg_info.values) {
+    array_destroy(msg->msg_info.values);
+  }
+  if (msg->msg_info.optionals) {
+    array_destroy(msg->msg_info.optionals);
+  }
+
   if (msg->additional_each_rspmgrs) {
     ASSERT(msg->consistency == DC_EACH_SAFE_QUORUM);
     // Only requests have their connection's owner as the 'struct server_pool' object,