Strange code in diff-delta.c

I am currently looking what can be done to speed up deltaing. The following code can be found here:

	for (i = 0; i < hsize; i++) {
		if (hash_count[i] < HASH_LIMIT)
			continue;
		entry = hash[i];
		do {
			struct index_entry *keep = entry;
			int skip = hash_count[i] / HASH_LIMIT / 2;
			do {
				entry = entry->next;
			} while(--skip && entry);
			keep->next = entry;
		} while(entry);
	}

If I analyze what happens for various values of hash_count[i], I get the following (the first case is by far the worst):

HASH_LIMIT <= hash_count[i] < 2*HASH_LIMIT:
  skip = 0;
  do .. while terminates with negative skip and entry == 0, keep->next
  is set to 0 -> all hashes except the first one get dropped.
  Result is new_hash_count = 1.  Ugh, ugh, ugh.

2*HASH_LIMIT <= hash_count[i] < 4*HASH_LIMIT
  skip = 1;
  do .. while does one iteration, every second value is skipped,
  result is that HASH_LIMIT <= new_hash_count < 2*HASH_LIMIT

4*HASH_LIMIT <= hash_limit[i] < 6*HASH_LIMIT
  skip = 2;
  do .. while does two iterations, two of three values are skipped,
  result is that 4*HASH_LIMIT/3 <= new_hash_count < 2*HASH_LIMIT

And so on. It would appear that if HASH_LIMIT is supposed to do what it is seemingly intended for, the skip calculation has to be just

			int skip = hash_count[i] / HASH_LIMIT;

Otherwise, there is completely broken behavior for values between HASH_LIMIT and 2*HASH_LIMIT (where only a single hash survives), and for larger values, the limit will be 2*HASH_LIMIT rather than HASH_LIMIT as was probably intended.