I just found that Issue #1739 is not totally resolved after the revision: f19a96e

Issue #1739 stated that mode_str in the following code may be null and may cause a null pointer dereference bug when calling strcmp.

 char *mode_str = to_string(value); 
 if (strcmp(mode_str, "tcp_only") == 0)  conf.mode = TCP_ONLY;

Then the developer revised as below (f19a96e), which cannot avoid the null pointer dereference.

 char *mode_str = to_string(value); 
 if (mode_str == NULL) conf.mode = TCP_ONLY;
 if (strcmp(mode_str, "tcp_only") == 0)  conf.mode = TCP_ONLY;

In my opinion, an "else" should be put at the beginning of the second if statement.