Intervals - Interval List Intersections
Examine the following code snippet for interval intersections. What is the subtle bug?
```python
def intervalIntersection(A, B):
i, j = 0, 0
result = []
while i < len(A) and j < len(B):
if A[i][1] <= B[j][0]:
i += 1
elif B[j][1] < A[i][0]:
j += 1
else:
start = max(A[i][0], B[j][0])
end = min(A[i][1], B[j][1])
result.append([start, end])
if A[i][1] < B[j][1]:
i += 1
else:
j += 1
return result
```