gistfile1.c

#include <stdio.h>
#include <stdlib.h>
#include <librsync.h>

int
main()
{
    FILE *base, *sig;
    base = fopen("oldfile", "rb");
    sig = fopen("sigfile", "wb");
    if (rs_sig_file(base, sig, RS_DEFAULT_BLOCK_LEN, RS_DEFAULT_STRONG_LEN, NULL) == RS_DONE)
        return -1;
    else
        return 0;
}

Confirmed: rs_sig_file in either arg seg faults. fopen does not. No confidence of actually working (needs more testing). Update: works on both gcc-4.2 and llvm-gcc

I see no errors and sigfile has something in it, that's my best guess for working state :P