convert mysql encoding name to iconv name

Author: sidorares

test/integration/connection/encoding/test-charset-results.js

@@ -9,7 +9,11 @@ function tryEncoding (encoding, cb) {
   connection.query('set character_set_results = ?', [encoding], function (err) {
     connection.query('SELECT ?', [payload], function (err, rows, fields) {
       assert.ifError(err);
-      assert.equal(mysql.CharsetToEncoding[fields[0].characterSet], encoding);
+      var iconvEncoding = encoding;
+      if (encoding == 'utf8mb4') {
+        iconvEncoding = 'utf8';
+      }
+      assert.equal(mysql.CharsetToEncoding[fields[0].characterSet], iconvEncoding);
       assert.equal(fields[0].name, payload);
       assert.equal(rows[0][fields[0].name], payload);
       cb();
@@ -20,7 +24,7 @@ function tryEncoding (encoding, cb) {
 tryEncoding('cp1251', function () {
   tryEncoding('koi8r', function () {
     tryEncoding('cp866', function () {
-      tryEncoding('utf8', function () {
+      tryEncoding('utf8mb4', function () {
         connection.end();
       });
     });