/* Determine index hash size. Note that indexing skips the
first byte to allow for optimizing the Rabin's polynomial
initialization in create_delta(). */
- entries = (bufsize - 1) / RABIN_WINDOW;
+ entries = (bufsize - 1) / RABIN_WINDOW;
+ if (bufsize >= 0xffffffffUL) {
+ /*
+ * Current delta format can't encode offsets into
+ * reference buffer with more than 32 bits.
+ */
+ entries = 0xfffffffeU / RABIN_WINDOW;
+ }
hsize = entries / 4;
for (i = 4; (1u << i) < hsize && i < 31; i++);
hsize = 1 << i;