diff --git a/blocks/variables_dynamic.js b/blocks/variables_dynamic.js
index 5d523f7e3..78598068b 100644
--- a/blocks/variables_dynamic.js
+++ b/blocks/variables_dynamic.js
@@ -98,11 +98,11 @@ Blockly.Constants.VariablesDynamic.CUSTOM_CONTEXT_MENU_VARIABLE_GETTER_SETTER_MI
      */
   customContextMenu: function(options) {
     // Getter blocks have the option to create a setter block, and vice versa.
-    if(this.isInFlyout){
+    if (this.isInFlyout) {
       return;
     }
-    var opposite_type ;
-    var contextMenuMsg ;
+    var opposite_type;
+    var contextMenuMsg;
     if (this.type == 'variables_get_dynamic') {
       opposite_type = 'variables_set_dynamic';
       contextMenuMsg = Blockly.Msg.VARIABLES_GET_CREATE_SET;
@@ -124,8 +124,8 @@ Blockly.Constants.VariablesDynamic.CUSTOM_CONTEXT_MENU_VARIABLE_GETTER_SETTER_MI
     options.push(option);
   },
   onchange: function() {
-    var name = this.getFieldValue('VAR');
-    var variableModel = this.workspace.getVariable(name);
+    var id = this.getFieldValue('VAR');
+    var variableModel = this.workspace.getVariableById(id);
     if (this.type == 'variables_get_dynamic') {
       this.outputConnection.setCheck(variableModel.type);
     } else {
diff --git a/core/extensions.js b/core/extensions.js
index 1ce582cc1..774233c8d 100644
--- a/core/extensions.js
+++ b/core/extensions.js
@@ -74,6 +74,9 @@ Blockly.Extensions.register = function(name, initFn) {
  *     registered.
  */
 Blockly.Extensions.registerMixin = function(name, mixinObj) {
+  if (!goog.isObject(mixinObj)){
+    throw new Error('Error: Mixin "' + name + '" must be a object');
+  }
   Blockly.Extensions.register(name, function() {
     this.mixin(mixinObj);
   });
diff --git a/core/flyout_base.js b/core/flyout_base.js
index 29ca24d18..6ee69aa30 100644
--- a/core/flyout_base.js
+++ b/core/flyout_base.js
@@ -269,6 +269,9 @@ Blockly.Flyout.prototype.init = function(targetWorkspace) {
 
   this.workspace_.renameVariableById =
       this.targetWorkspace_.renameVariableById.bind(this.targetWorkspace_);
+
+  this.workspace_.getVariableTypes =
+      this.targetWorkspace_.getVariableTypes.bind(this.targetWorkspace_);
 };
 
 /**
diff --git a/core/variable_map.js b/core/variable_map.js
index 5081db09a..0995d4fdd 100644
--- a/core/variable_map.js
+++ b/core/variable_map.js
@@ -247,11 +247,21 @@ Blockly.VariableMap.prototype.getVariablesOfType = function(type) {
 };
 
 /**
- * Return all variable types.
+ * Return all variable types.  This list always contains the empty string.
  * @return {!Array.<string>} List of variable types.
  */
 Blockly.VariableMap.prototype.getVariableTypes = function() {
-  return Object.keys(this.variableMap_);
+  var types = Object.keys(this.variableMap_);
+  var hasEmpty = false;
+  for (var i = 0; i < types.length; i++) {
+    if (types[i] == '') {
+      hasEmpty = true;
+    }
+  }
+  if (!hasEmpty) {
+    types.push('');
+  }
+  return types;
 };
 
 /**
diff --git a/tests/generators/unittest_dart.js b/tests/generators/unittest_dart.js
index 75b165df4..97e6ae466 100644
--- a/tests/generators/unittest_dart.js
+++ b/tests/generators/unittest_dart.js
@@ -62,13 +62,10 @@ Blockly.Dart['unittest_main'] = function(block) {
   // Run tests (unindented).
   code += Blockly.Dart.statementToCode(block, 'DO')
       .replace(/^  /, '').replace(/\n  /g, '\n');
-  var reportVar = Blockly.Dart.variableDB_.getDistinctName(
-      'report', Blockly.Variables.NAME_TYPE);
-  code += 'String ' + reportVar + ' = ' + functionName + '();\n';
+  // Print the report to the console (that's where errors will go anyway).
+  code += 'print(' + functionName + '());\n';
   // Destroy results.
   code += resultsVar + ' = null;\n';
-  // Print the report to the console (that's where errors will go anyway).
-  code += 'print(' + reportVar + ');\n';
   return code;
 };
 
@@ -143,8 +140,7 @@ Blockly.Dart['unittest_fail'] = function(block) {
   // Always assert an error.
   var resultsVar = Blockly.Dart.variableDB_.getName('unittestResults',
       Blockly.Variables.NAME_TYPE);
-  var message = Blockly.Dart.valueToCode(block, 'MESSAGE',
-      Blockly.Dart.ORDER_NONE) || '';
+  var message = Blockly.Dart.quote_(block.getFieldValue('MESSAGE'));
   var functionName = Blockly.Dart.provideFunction_(
       'unittest_fail',
       [ 'void ' + Blockly.Dart.FUNCTION_NAME_PLACEHOLDER_ +
diff --git a/tests/generators/unittest_javascript.js b/tests/generators/unittest_javascript.js
index db9d62ff1..9fda5be30 100644
--- a/tests/generators/unittest_javascript.js
+++ b/tests/generators/unittest_javascript.js
@@ -63,13 +63,10 @@ Blockly.JavaScript['unittest_main'] = function(block) {
   // Run tests (unindented).
   code += Blockly.JavaScript.statementToCode(block, 'DO')
       .replace(/^  /, '').replace(/\n  /g, '\n');
-  var reportVar = Blockly.JavaScript.variableDB_.getDistinctName(
-      'report', Blockly.Variables.NAME_TYPE);
-  code += 'var ' + reportVar + ' = ' + functionName + '();\n';
+  // Send the report to the console (that's where errors will go anyway).
+  code += 'console.log(' + functionName + '());\n';
   // Destroy results.
   code += resultsVar + ' = null;\n';
-  // Send the report to the console (that's where errors will go anyway).
-  code += 'console.log(' + reportVar + ');\n';
   return code;
 };
 
@@ -147,8 +144,7 @@ Blockly.JavaScript['unittest_fail'] = function(block) {
   // Always assert an error.
   var resultsVar = Blockly.JavaScript.variableDB_.getName('unittestResults',
       Blockly.Variables.NAME_TYPE);
-  var message = Blockly.JavaScript.valueToCode(block, 'MESSAGE',
-      Blockly.JavaScript.ORDER_NONE) || '';
+  var message = Blockly.JavaScript.quote_(block.getFieldValue('MESSAGE'));
   var functionName = Blockly.JavaScript.provideFunction_(
       'unittest_fail',
       [ 'function ' + Blockly.JavaScript.FUNCTION_NAME_PLACEHOLDER_ +
diff --git a/tests/generators/unittest_lua.js b/tests/generators/unittest_lua.js
index d687b091b..73c5dbe0d 100644
--- a/tests/generators/unittest_lua.js
+++ b/tests/generators/unittest_lua.js
@@ -61,13 +61,10 @@ Blockly.Lua['unittest_main'] = function(block) {
   // Run tests (unindented).
   code += Blockly.Lua.statementToCode(block, 'DO')
       .replace(/^  /, '').replace(/\n  /g, '\n');
-  var reportVar = Blockly.Lua.variableDB_.getDistinctName(
-      'report', Blockly.Variables.NAME_TYPE);
-  code += reportVar + ' = ' + functionName + '()\n';
+  // Print the report.
+  code += 'print(' + functionName + '())\n';
   // Destroy results.
   code += resultsVar + ' = nil\n';
-  // Print the report.
-  code += 'print(' + reportVar + ')\n';
   return code;
 };
 
@@ -153,8 +150,7 @@ Blockly.Lua['unittest_fail'] = function(block) {
   // Always assert an error.
   var resultsVar = Blockly.Lua.variableDB_.getName('unittestResults',
       Blockly.Variables.NAME_TYPE);
-  var message = Blockly.Lua.valueToCode(block, 'MESSAGE',
-      Blockly.Lua.ORDER_NONE) || '';
+  var message = Blockly.Lua.quote_(block.getFieldValue('MESSAGE'));
   var functionName = Blockly.Lua.provideFunction_(
       'unittest_fail',
       ['function ' + Blockly.Lua.FUNCTION_NAME_PLACEHOLDER_ + '(message)',
diff --git a/tests/generators/unittest_php.js b/tests/generators/unittest_php.js
index 28e6b2799..528e5971d 100644
--- a/tests/generators/unittest_php.js
+++ b/tests/generators/unittest_php.js
@@ -25,147 +25,124 @@
 'use strict';
 
 Blockly.PHP['unittest_main'] = function(block) {
-    // Container for unit tests.
-    var resultsVar = Blockly.PHP.variableDB_.getName('unittestResults',
-        Blockly.Variables.NAME_TYPE);
-    var functionName = Blockly.PHP.provideFunction_(
-        'unittest_report',
-        [ 'function ' + Blockly.PHP.FUNCTION_NAME_PLACEHOLDER_ + '() {',
-            'global ' + resultsVar + ';',
-            '  // Create test report.',
-            '  $report = array();',
-            '  $summary = array();',
-            '  $fails = 0;',
-            '  for ($x = 0; $x < count(' + resultsVar + '); $x++) {',
-            '    if (' + resultsVar + '[$x][0]) {',
-            '      array_push($summary, ".");',
-            '    } else {',
-            '      array_push($summary, "F");',
-            '      $fails++;',
-            '      array_push($report,"");',
-            '      array_push($report, "FAIL: " . ' + resultsVar + '[$x][2]);',
-            '      array_push($report, ' + resultsVar + '[$x][1]);',
-            '    }',
-            '  }',
-            '  array_unshift($report, implode("",$summary));',
-            '  array_push($report, "");',
-            '  array_push($report, "Number of tests run: " . count(' + resultsVar + '));',
-            '  array_push($report, "");',
-            '  if ($fails) {',
-            '    array_push($report, "FAILED (failures=" . $fails + ")");',
-            '  } else {',
-            '    array_push($report, "OK");',
-            '  }',
-            '  return implode("\\n", $report);',
-            '}']);
-    // Setup global to hold test results.
-    var code = resultsVar + ' = array();\n';
-    // Run tests (unindented).
-    code += Blockly.PHP.statementToCode(block, 'DO')
-        .replace(/^  /, '').replace(/\n  /g, '\n');
-    var reportVar = Blockly.PHP.variableDB_.getDistinctName(
-        'report', Blockly.Variables.NAME_TYPE);
-    code += reportVar + ' = ' + functionName + '();\n';
-    // Destroy results.
-    code += resultsVar + ' = null;\n';
-    // Send the report to the console (that's where errors will go anyway).
-    code += 'print(' + reportVar + ');\n';
-    return code;
+  // Container for unit tests.
+  var resultsVar = Blockly.PHP.variableDB_.getName('unittestResults',
+      Blockly.Variables.NAME_TYPE);
+  var functionName = Blockly.PHP.provideFunction_(
+      'unittest_report',
+      [ 'function ' + Blockly.PHP.FUNCTION_NAME_PLACEHOLDER_ + '() {',
+          '  global ' + resultsVar + ';',
+          '  // Create test report.',
+          '  $report = array();',
+          '  $summary = array();',
+          '  $fails = 0;',
+          '  for ($x = 0; $x < count(' + resultsVar + '); $x++) {',
+          '    if (' + resultsVar + '[$x][0]) {',
+          '      array_push($summary, ".");',
+          '    } else {',
+          '      array_push($summary, "F");',
+          '      $fails++;',
+          '      array_push($report, "");',
+          '      array_push($report, "FAIL: " . ' + resultsVar + '[$x][2]);',
+          '      array_push($report, ' + resultsVar + '[$x][1]);',
+          '    }',
+          '  }',
+          '  array_unshift($report, implode("", $summary));',
+          '  array_push($report, "");',
+          '  array_push($report, "Number of tests run: " . count(' + resultsVar + '));',
+          '  array_push($report, "");',
+          '  if ($fails) {',
+          '    array_push($report, "FAILED (failures=" . $fails + ")");',
+          '  } else {',
+          '    array_push($report, "OK");',
+          '  }',
+          '  return implode("\\n", $report);',
+          '}']);
+  // Setup global to hold test results.
+  var code = resultsVar + ' = array();\n';
+  // Run tests (unindented).
+  code += Blockly.PHP.statementToCode(block, 'DO')
+      .replace(/^  /, '').replace(/\n  /g, '\n');
+  // Send the report to the console (that's where errors will go anyway).
+  code += 'print(' + functionName + '());\n';
+  // Destroy results.
+  code += resultsVar + ' = null;\n';
+  return code;
 };
 
 Blockly.PHP['unittest_main'].defineAssert_ = function(block) {
-    var resultsVar = Blockly.PHP.variableDB_.getName('unittestResults',
-        Blockly.Variables.NAME_TYPE);
-    var functionName = Blockly.PHP.provideFunction_(
-        'assertEquals',
-       ['  function equals($a, $b) {',
-        '    if ($a === $b) {',
-        '      return true;',
-        '    } else if ((is_numeric($a)) && (is_numeric($b)) &&',
-        '        (round($a,15) == round($b,15))) {',
-        '      return true;',
-        '    } else if (is_array($a) && is_array($b)) {',
-        '      if (count($a) != count($b)) {',
-        '        return false;',
-        '      }',
-        '      for ($i = 0; $i < count($a); $i++) {',
-        '        if (!equals($a[$i], $b[$i])) {',
-        '          return false;',
-        '        }',
-        '      }',
-        '      return true;',
-        '    }',
-        '    return false;',
-        '  }',
-        'function ' + Blockly.PHP.FUNCTION_NAME_PLACEHOLDER_ +
-        '($actual, $expected, $message) {',
-        'global ' + resultsVar + ';',
-        '  // Asserts that a value equals another value.',
-        '  if (!is_array(' + resultsVar + ')) {',
-        '    throw new Exception("Orphaned assert: " . $message);',
-        '  }',
-        '  if (equals($actual, $expected)) {',
-        '    array_push(' + resultsVar + ', [true, "OK", $message]);',
-        '  } else {',
-        '    $expected = is_array($expected) ? implode(" ", $expected) : ' +
-            '$expected;',
-        '    $actual = is_array($actual) ? implode(" ", $actual) : ' +
-            '$actual;',
-        '    array_push(' + resultsVar + ', [false, ' +
-        '"Expected: " . $expected . "\\nActual: " . $actual, $message]);',
-        '  }',
-        '}']);
-    return functionName;
+  var resultsVar = Blockly.PHP.variableDB_.getName('unittestResults',
+      Blockly.Variables.NAME_TYPE);
+  var functionName = Blockly.PHP.provideFunction_(
+      'assertEquals',
+      ['function ' + Blockly.PHP.FUNCTION_NAME_PLACEHOLDER_ +
+      '($actual, $expected, $message) {',
+      '  global ' + resultsVar + ';',
+      '  // Asserts that a value equals another value.',
+      '  if (!is_array(' + resultsVar + ')) {',
+      '    throw new Exception("Orphaned assert: " . $message);',
+      '  }',
+      '  if ($actual == $expected) {',
+      '    array_push(' + resultsVar + ', [true, "OK", $message]);',
+      '  } else {',
+      '    $expected = is_array($expected) ? implode(" ", $expected) : ' +
+          '$expected;',
+      '    $actual = is_array($actual) ? implode(" ", $actual) : ' +
+          '$actual;',
+      '    array_push(' + resultsVar + ', [false, ' +
+      '"Expected: " . $expected . "\\nActual: " . $actual, $message]);',
+      '  }',
+      '}']);
+  return functionName;
 };
 
 Blockly.PHP['unittest_assertequals'] = function(block) {
-    // Asserts that a value equals another value.
-    var message = Blockly.PHP.valueToCode(block, 'MESSAGE',
-      Blockly.PHP.ORDER_NONE) || '';
-    var actual = Blockly.PHP.valueToCode(block, 'ACTUAL',
-            Blockly.PHP.ORDER_COMMA) || 'null';
-    var expected = Blockly.PHP.valueToCode(block, 'EXPECTED',
-            Blockly.PHP.ORDER_COMMA) || 'null';
-    return Blockly.PHP['unittest_main'].defineAssert_() +
-        '(' + actual + ', ' + expected + ', ' + message + ');\n';
+  // Asserts that a value equals another value.
+  var message = Blockly.PHP.valueToCode(block, 'MESSAGE',
+    Blockly.PHP.ORDER_NONE) || '';
+  var actual = Blockly.PHP.valueToCode(block, 'ACTUAL',
+          Blockly.PHP.ORDER_COMMA) || 'null';
+  var expected = Blockly.PHP.valueToCode(block, 'EXPECTED',
+          Blockly.PHP.ORDER_COMMA) || 'null';
+  return Blockly.PHP['unittest_main'].defineAssert_() +
+      '(' + actual + ', ' + expected + ', ' + message + ');\n';
 };
 
 Blockly.PHP['unittest_assertvalue'] = function(block) {
-    // Asserts that a value is true, false, or null.
-    var message = Blockly.PHP.valueToCode(block, 'MESSAGE',
-      Blockly.PHP.ORDER_NONE) || '';
-    var actual = Blockly.PHP.valueToCode(block, 'ACTUAL',
-            Blockly.PHP.ORDER_COMMA) || 'null';
-    var expected = block.getFieldValue('EXPECTED');
-    if (expected == 'TRUE') {
-        expected = 'true';
-    } else if (expected == 'FALSE') {
-        expected = 'false';
-    } else if (expected == 'NULL') {
-        expected = 'null';
-    }
-    return Blockly.PHP['unittest_main'].defineAssert_() +
-        '(' + actual + ', ' + expected + ', ' + message + ');\n';
+  // Asserts that a value is true, false, or null.
+  var message = Blockly.PHP.valueToCode(block, 'MESSAGE',
+    Blockly.PHP.ORDER_NONE) || '';
+  var actual = Blockly.PHP.valueToCode(block, 'ACTUAL',
+          Blockly.PHP.ORDER_COMMA) || 'null';
+  var expected = block.getFieldValue('EXPECTED');
+  if (expected == 'TRUE') {
+      expected = 'true';
+  } else if (expected == 'FALSE') {
+      expected = 'false';
+  } else if (expected == 'NULL') {
+      expected = 'null';
+  }
+  return Blockly.PHP['unittest_main'].defineAssert_() +
+      '(' + actual + ', ' + expected + ', ' + message + ');\n';
 };
 
 Blockly.PHP['unittest_fail'] = function(block) {
-    // Always assert an error.
-    var resultsVar = Blockly.PHP.variableDB_.getName('unittestResults',
-        Blockly.Variables.NAME_TYPE);
-    var message = Blockly.PHP.valueToCode(block, 'MESSAGE',
-      Blockly.PHP.ORDER_NONE) || '';
-    var functionName = Blockly.PHP.provideFunction_(
-        'unittest_fail',
-        [ 'function ' + Blockly.PHP.FUNCTION_NAME_PLACEHOLDER_ +
-        '($message) {',
-            'global ' + resultsVar + ';',
-            '  // Always assert an error.',
-            '  if (!' + resultsVar + ') {',
-            '    throw new Exception("Orphaned assert fail: " . $message);',
-            '  }',
-            '  array_push(' + resultsVar + ', [false, "Fail.", $message]);',
-            '}']);
-    return functionName + '(' + message + ');\n';
+  // Always assert an error.
+  var resultsVar = Blockly.PHP.variableDB_.getName('unittestResults',
+      Blockly.Variables.NAME_TYPE);
+  var message = Blockly.PHP.quote_(block.getFieldValue('MESSAGE'));
+  var functionName = Blockly.PHP.provideFunction_(
+      'unittest_fail',
+      [ 'function ' + Blockly.PHP.FUNCTION_NAME_PLACEHOLDER_ +
+      '($message) {',
+          '  global ' + resultsVar + ';',
+          '  // Always assert an error.',
+          '  if (!' + resultsVar + ') {',
+          '    throw new Exception("Orphaned assert fail: " . $message);',
+          '  }',
+          '  array_push(' + resultsVar + ', [false, "Fail.", $message]);',
+          '}']);
+  return functionName + '(' + message + ');\n';
 };
 
 Blockly.PHP['unittest_adjustindex'] = function(block) {
diff --git a/tests/generators/unittest_python.js b/tests/generators/unittest_python.js
index 7fbe313b1..5e00e26be 100644
--- a/tests/generators/unittest_python.js
+++ b/tests/generators/unittest_python.js
@@ -59,13 +59,10 @@ Blockly.Python['unittest_main'] = function(block) {
   // Run tests (unindented).
   code += Blockly.Python.statementToCode(block, 'DO')
       .replace(/^  /, '').replace(/\n  /g, '\n');
-  var reportVar = Blockly.Python.variableDB_.getDistinctName(
-      'report', Blockly.Variables.NAME_TYPE);
-  code += reportVar + ' = ' + functionName + '()\n';
+  // Print the report.
+  code += 'print(' + functionName + '())\n';
   // Destroy results.
   code += resultsVar + ' = None\n';
-  // Print the report.
-  code += 'print(' + reportVar + ')\n';
   return code;
 };
 
@@ -121,8 +118,7 @@ Blockly.Python['unittest_fail'] = function(block) {
   // Always assert an error.
   var resultsVar = Blockly.Python.variableDB_.getName('unittestResults',
       Blockly.Variables.NAME_TYPE);
-  var message = Blockly.Python.valueToCode(block, 'MESSAGE',
-      Blockly.Python.ORDER_NONE) || '';
+  var message = Blockly.Python.quote_(block.getFieldValue('MESSAGE'));
   var functionName = Blockly.Python.provideFunction_(
       'fail',
       ['def ' + Blockly.Python.FUNCTION_NAME_PLACEHOLDER_ + '(message):',
diff --git a/tests/jsunit/field_variable_test.js b/tests/jsunit/field_variable_test.js
index 6d3ef9d66..bc36b7d69 100644
--- a/tests/jsunit/field_variable_test.js
+++ b/tests/jsunit/field_variable_test.js
@@ -175,7 +175,8 @@ function test_fieldVariable_getVariableTypes_nullVariableTypes() {
   fieldVariable.variableTypes = null;
 
   var resultTypes = fieldVariable.getVariableTypes_();
-  isEqualArrays(resultTypes, ['type1', 'type2']);
+  // The empty string is always one of the options.
+  isEqualArrays(resultTypes, ['type1', 'type2', '']);
   workspace.dispose();
 }
 
diff --git a/tests/jsunit/variable_map_test.js b/tests/jsunit/variable_map_test.js
index 568ce0b0d..3ccf674e2 100644
--- a/tests/jsunit/variable_map_test.js
+++ b/tests/jsunit/variable_map_test.js
@@ -269,14 +269,16 @@ function test_getVariableTypes_Trivial() {
   variable_map.createVariable('name3', 'type2', 'id3');
   variable_map.createVariable('name4', 'type3', 'id4');
   var result_array = variable_map.getVariableTypes();
-  isEqualArrays(['type1', 'type2', 'type3'], result_array);
+  // The empty string is always an option.
+  isEqualArrays(['type1', 'type2', 'type3', ''], result_array);
   variableMapTest_tearDown();
 }
 
 function test_getVariableTypes_None() {
   variableMapTest_setUp();
+  // The empty string is always an option.
   var result_array = variable_map.getVariableTypes();
-  isEqualArrays([], result_array);
+  isEqualArrays([''], result_array);
   variableMapTest_tearDown();
 }