Possibly bad logic in evalfunction.c:FnCallSelectServers

In evalfunction.c:FnCallSelectServers I believe there is something wrong with the logic.

The following piece of code will assign a nullbyte to recvbuf[-1] if there is no message in the socket.

char recvbuf[CF_BUFSIZE];
ssize_t n_read = recv(sd, recvbuf, maxbytes, 0);

if (n_read < 0)
{
    /* maxbytes was checked earlier, but just make sure... */
    assert((size_t) n_read < sizeof(recvbuf));
    recvbuf[n_read] = '\0';

I believe the condition in the if statement should be (n_read >= 0) in stead of (n_read < 0)

 This seems to only affect 3.18. In 3.15 and 3.12 the condition is (n_read != -1)