buffer: fix out of range for toString

Author: jazelly

lib/buffer.js

@@ -843,12 +843,12 @@ Buffer.prototype.toString = function toString(encoding, start, end) {
  else if (start >= len)
  return '';
  else
- start |= 0;
+ start = MathTrunc(start) || 0;
 
  if (end === undefined || end > len)
  end = len;
  else
- end |= 0;
+ end = MathTrunc(end) || 0;
 
  if (end <= start)
  return '';

test/parallel/test-buffer-tostring-range.js

@@ -98,3 +98,8 @@ assert.throws(() => {
  name: 'TypeError',
  message: 'Unknown encoding: null'
 });
+
+
+const largeBuffer = Buffer.alloc(2 ** 32);
+// Must not throw when start and end are within kMaxLength
+largeBuffer.toString('utf8', 2 ** 31 + 1, 2 ** 31 + 10);