1 files changed, 33 insertions, 0 deletions
diff --git a/lib/string_decoder.js b/lib/string_decoder.js
index 879e59064..6b1e30895 100644
--- a/lib/string_decoder.js
+++ b/lib/string_decoder.js
@@ -19,8 +19,15 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
+function assertEncoding(encoding) {
+  if (encoding && !Buffer.isEncoding(encoding)) {
+    throw new Error('Unknown encoding: ' + encoding);
+  }
+}
+
 var StringDecoder = exports.StringDecoder = function(encoding) {
   this.encoding = (encoding || 'utf8').toLowerCase().replace(/[-_]/, '');
+  assertEncoding(encoding);
   switch (this.encoding) {
     case 'utf8':
       // CESU-8 represents each of Surrogate Pair by 3-bytes
@@ -32,6 +39,11 @@ var StringDecoder = exports.StringDecoder = function(encoding) {
       this.surrogateSize = 2;
       this.detectIncompleteChar = utf16DetectIncompleteChar;
       break;
+    case 'base64':
+      // Base-64 stores 3 bytes in 4 chars, and pads the remainder.
+      this.surrogateSize = 3;
+      this.detectIncompleteChar = base64DetectIncompleteChar;
+      break;
     default:
       this.write = passThroughWrite;
       return;
@@ -145,6 +157,21 @@ StringDecoder.prototype.detectIncompleteChar = function(buffer) {
   return i;
 };
 
+StringDecoder.prototype.end = function(buffer) {
+  var res = '';
+  if (buffer && buffer.length)
+    res = this.write(buffer);
+
+  if (this.charReceived) {
+    var cr = this.charReceived;
+    var buf = this.charBuffer;
+    var enc = this.encoding;
+    res += buf.slice(0, cr).toString(enc);
+  }
+
+  return res;
+};
+
 function passThroughWrite(buffer) {
   return buffer.toString(this.encoding);
 }
@@ -154,3 +181,9 @@ function utf16DetectIncompleteChar(buffer) {
   this.charLength = incomplete ? 2 : 0;
   return incomplete;
 }
+
+function base64DetectIncompleteChar(buffer) {
+  var incomplete = this.charReceived = buffer.length % 3;
+  this.charLength = incomplete ? 3 : 0;
+  return incomplete;
+}