buffer: fix backwards incompatibility

4a86803f6 introduced a backwards incompatibility by accident
and was not caught due to an existing test that wasn't strict enough.

This commit fixes both the backwards incompatibility and the test.

PR-URL: https://github.com/nodejs/node/pull/12439
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 1 insertions, 4 deletions

diff --git a/lib/buffer.js b/lib/buffer.js
index 87bdfd2d95..5450861d04 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -456,10 +456,7 @@ function byteLength(string, encoding) {
         return len >>> 1;
       break;
   }
-  if (mustMatch)
-    throw new TypeError('Unknown encoding: ' + encoding);
-  else
-    return binding.byteLengthUtf8(string);
+  return (mustMatch ? -1 : binding.byteLengthUtf8(string));
 }
 
 Buffer.byteLength = byteLength;