- int32 i2;
- for (i2 = i; i2 >= 0; i2 = s->sums[i2].chain) {
- if (s->sums[i2].offset != offset)
- continue;
- if (i2 != i) {
- if (sum != s->sums[i2].sum1)
- break;
- if (memcmp(sum2, s->sums[i2].sum2,
- s->s2length) != 0)
- break;
- i = i2;
+ /* All the generator's chunks start at blength boundaries. */
+ while (aligned_offset < offset)
+ aligned_offset += s->blength;
+ if (offset == aligned_offset) {
+ int32 i2;
+ for (i2 = i; i2 >= 0; i2 = s->sums[i2].chain) {
+ if (s->sums[i2].offset != offset)
+ continue;
+ if (i2 != i) {
+ if (sum != s->sums[i2].sum1
+ || memcmp(sum2, s->sums[i2].sum2, s->s2length) != 0)
+ break;
+ i = i2;
+ }
+ /* This chunk remained in the same spot in the old and new file. */
+ s->sums[i].flags |= SUMFLG_SAME_OFFSET;
+ want_i = i;