buffer: return uint if MSB is 1 in readUInt32

Fix issue where a signed integer is returned.

Example:

var b = new Buffer(4);
b.writeUInt32BE(0xffffffff);
b.readUInt32BE(0) == -1

Signed-off-by: Trevor Norris <trev.norris@gmail.com>

lib/buffer.js

@@ -476,8 +476,8 @@ 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]) >>> 0);
 };
 
 

test/simple/test-buffer.js

@@ -914,6 +914,13 @@ var buf = new Buffer(0);
 assert.throws(function() { buf.readUInt8(0); }, RangeError);
 assert.throws(function() { buf.readInt8(0); }, RangeError);
 
+var buf = new Buffer([0xFF]);
+
+assert.equal(buf.readUInt8(0), 255);
+assert.equal(buf.readInt8(0), -1);
+
+
+
 [16, 32].forEach(function(bits) {
   var buf = new Buffer(bits / 8 - 1);
 
@@ -934,6 +941,22 @@ assert.throws(function() { buf.readInt8(0); }, RangeError);
                 'readInt' + bits + 'LE()');
 });
 
+[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)));
+});
+
 // test Buffer slice
 (function() {
   var buf = new Buffer('0123456789');