buffer: fix sign overflow in readUIn32BE

`|` operation takes precendence on `+`, which will result in
`new Buffer('ffffffff', 16).readUInt32BE(0)` returning `-1` instead of
`ffffffff`.
This commit is contained in:
Fedor Indutny 2014-07-29 12:34:49 +04:00
parent 338ba2bc80
commit 38f6fcd822
2 changed files with 18 additions and 2 deletions

View File

@ -621,8 +621,8 @@ Buffer.prototype.readUInt32BE = function(offset, noAssert) {
return (this[offset] * 0x1000000) +
((this[offset + 1] << 16) |
(this[offset + 2] << 8)) |
(this[offset + 3]);
(this[offset + 2] << 8) |
this[offset + 3]);
};

View File

@ -964,6 +964,22 @@ assert.throws(function() { buf.readInt8(0); }, /beyond buffer length/);
);
});
[16, 32].forEach(function(bits) {
var buf = new Buffer([0xFF, 0xFF, 0xFF, 0xFF]);
assert.equal(buf['readUInt' + bits + 'BE'](0),
(0xFFFFFFFF >>> (32 - bits)));
assert.equal(buf['readUInt' + bits + 'LE'](0),
(0xFFFFFFFF >>> (32 - bits)));
assert.equal(buf['readInt' + bits + 'BE'](0),
(0xFFFFFFFF >> (32 - bits)));
assert.equal(buf['readInt' + bits + 'LE'](0),
(0xFFFFFFFF >> (32 - bits)));
});
// SlowBuffer sanity checks.
assert.throws(function() {
var len = 0xfffff;