Created attachment 24582 [details] [review]
Fix

In fccache.c, there is the line
    cache = mmap (0, fd_stat->st_size, PROT_READ, MAP_SHARED, fd, 0);
Furtheron there is the check
    if (!cache)
But mmap() returns MAP_FAILED on failure, which is (void *) -1, and not NULL. So if mmap() fails, the guard of that if-statement will evaluate to false, and no cache is allocated, resulting in a crash a few lines later at
    if (cache->magic != FC_CACHE_MAGIC_MMAP