PR_GetSystemInfo(PR_SI_HOSTNAME, ...) on Mac is returning a string containing the IP address converted to a string with the first '.' converted to '\0'. E.g. if my IP address is 12.34.56.78, it is returning (including terminating nulls): '12\0.34.56.78\0' Taken as a conventional C string, this is just "12"; which is not usable as a hostname. Looking at the code this seems to be a combination of two hacks: a) on Mac, there is no hostname, so the IP address in string form is being used instead b) somone (presumably later) added code inside PR_GetSystemInfo(PR_SI_HOSTNAME, ...) to convert a fully qualified hostname into an unqualified hostname by replacing the first '.' in the string with a '\0' (the code looks like it's trying to replace every '.' with a '\0', but it has a bug so it in fact only gets the first one). I have no idea why anyone would think that it was more useful to return an unqualified hostname than a fully qualified one (the caller can always convert a fully qualified one into an unqualified one, but not vice versa), but applied to an IP address used in place of a hostname this hack is fatal. This has resulted in the following nasty hack in my code where I undo the damage done by b): { char vBuf[SYS_INFO_BUFFER_LENGTH]; vBuf[SYS_INFO_BUFFER_LENGTH - 1] = '\0'; if (PR_SUCCESS == PR_GetSystemInfo(PR_SI_HOSTNAME, vBuf, SYS_INFO_BUFFER_LENGTH)) { PRHostEnt vHostEnt; char vBuf2[PR_NETDB_BUF_SIZE]; if (PR_SUCCESS == PR_GetHostByName(vBuf, vBuf2, PR_NETDB_BUF_SIZE, &vHostEnt)) { ... } /* Horible hack to fix broken NSPR implementation */ else if (CC_strlen(vBuf) < SYS_INFO_BUFFER_LENGTH - 1) { vBuf[CC_strlen(vBuf)] = '.'; if (PR_SUCCESS == PR_GetHostByName(vBuf, vBuf2, PR_NETDB_BUF_SIZE, &vHostEnt)) { ... } } } } Could someone please fix this?

*** This bug has been marked as a duplicate of 92516 ***