private static void condenseSharedRange(DiffLines left, DiffLines right, DiffLines newLeft,
			DiffLines newRight, int start, int end) {

		for (int i = start; i < end; i++) {
			ValidatableLine line1 = left.get(i);
			ValidatableLine line2 = right.get(i);

			if (line1.matches(line2)) {
				copyLine(left, newLeft, i);
				copyLine(right, newRight, i);
				continue;
			}

			int endOfRange = findEndOfDistinctLines(left, right, i);
			condenseSubRange(left, right, newLeft, newRight, i, endOfRange);

			// setup the next range match
			i = endOfRange - 1; // -1 since endOfRange is exclusive
		}
	}
Removes empty rows that are no longer necessary for alignment (it may add new empty rows)
Ghidra/Features/Base/src/main/java/ghidra/app/util/html/diff/DataTypeDiffBuilder.java