buffer: normalize compare() output

Because of differences in memcmp() implementation, normalize output to return -1, 0 or 1 only.
nodejs · Apr 29, 2014 · 113764f · 113764f
1 parent 26a1b71
commit 113764f
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Showing 2 changed files with 11 additions and 7 deletions.
diff --git a/src/node_buffer.cc b/src/node_buffer.cc
@@ -621,10 +621,14 @@ void Compare(const FunctionCallbackInfo<Value> &args) {
   size_t cmp_length = MIN(obj_a_len, obj_b_len);
 
   int32_t val = memcmp(obj_a_data, obj_b_data, cmp_length);
-  if (!val)
-    val = obj_a_len - obj_b_len;
 
-  args.GetReturnValue().Set(val);
+  if (val == 0 && obj_a_len != obj_b_len)
+    val = obj_a_len > obj_b_len ? 1 : -1;
+
+  if (val == 0)
+    args.GetReturnValue().Set(val);
+  else
+    args.GetReturnValue().Set(val > 0 ? 1 : -1);
 }
 
 

diff --git a/test/simple/test-buffer.js b/test/simple/test-buffer.js
@@ -1043,13 +1043,13 @@ var b = new Buffer(1).fill('a');
 var c = new Buffer(1).fill('c');
 var d = new Buffer(2).fill('aa');
 
-assert.equal(b.compare(c), -2);
-assert.equal(c.compare(d), 2);
+assert.equal(b.compare(c), -1);
+assert.equal(c.compare(d), 1);
 assert.equal(d.compare(b), 1);
 assert.equal(b.compare(d), -1);
 
-assert.equal(Buffer.compare(b, c), 2);
-assert.equal(Buffer.compare(c, d), -2);
+assert.equal(Buffer.compare(b, c), 1);
+assert.equal(Buffer.compare(c, d), -1);
 assert.equal(Buffer.compare(d, b), -1);
 assert.equal(Buffer.compare(b, d), 1);