Intervals - Insert Interval
Consider this buggy insert interval code snippet. Which line contains the subtle bug that can cause incorrect merges when intervals just touch at boundaries?
```python
def insert(intervals, newInterval):
intervals.append(newInterval)
intervals.sort(key=lambda x: x[0])
merged = [intervals[0]]
for i in range(1, len(intervals)):
if intervals[i][0] < merged[-1][1]:
merged[-1][1] = max(merged[-1][1], intervals[i][1])
else:
merged.append(intervals[i])
return merged
```