Read functions revert to reading from shm when file pointer is NULL

[DemonTPx]

I noticed something weird with the read functions where would be read from shm, even though IP2LOCATION_FILE_IO is configured as the access type when the file pointer is NULL.

Consider this snipper from the IP2Location_read32 function in IP2Loc_DBInterface.c:

if (DB_access_type == IP2LOCATION_FILE_IO && handle != NULL)
{
    // reads from file
}
else
{
    // reads from shm
}

I think the handle != NULL check should be done one level deeper. However, I'm not sure what the function should return in that case.

The following code would obviously result in a segfault:

auto db = IP2Location_open("data/IP-COUNTRY-SAMPLE.BIN");
db->filehandle = NULL;

auto record = IP2Location_get_all(db, "127.0.0.1");