[[FIX]] block scope vars dont redefine in blocks

Do give a redefinition error when a block scope declaration is inside a
block.
Fixes #2438

src/jshint.js

@@ -3350,7 +3350,7 @@ var JSHINT = (function() {
       for (var t in tokens) {
         if (tokens.hasOwnProperty(t)) {
           t = tokens[t];
-          if (state.funct["(global)"]) {
+          if (state.funct["(scope)"].block.isGlobal()) {
             if (predefined[t.id] === false) {
               warning("W079", t.token, t.id);
             }
@@ -4384,7 +4384,7 @@ var JSHINT = (function() {
       ok = false;
     }
 
-    if (!state.funct["(global)"] || !state.funct["(scope)"].atTop()) {
+    if (!state.funct["(scope)"].block.isGlobal()) {
       error("E053", state.tokens.curr);
       ok = false;
     }

src/scope-manager.js

@@ -472,10 +472,6 @@ var scopeManager = function(state, predefined, exported, declared) {
       return null;
     },
 
-    atTop: function() {
-      return _scopeStack.length === 1;
-    },
-
     /**
      * for the exported options, indicating a variable is used outside the file
      */
@@ -641,6 +637,15 @@ var scopeManager = function(state, predefined, exported, declared) {
     },
 
     block: {
+
+      /**
+       * is the current block global?
+       * @returns Boolean
+       */
+      isGlobal: function() {
+        return _current["(global)"];
+      },
+
       use: function(labelName, token) {
 
         // if resolves to current function params, then do not store usage just resolve

tests/unit/parser.js

@@ -2760,6 +2760,20 @@ exports["make sure variables may shadow globals in functions after they are refe
   test.done();
 };
 
+exports["test block scope redefines globals only outside of blocks"] = function (test) {
+  var code = [
+    "{",
+    "  let Map = true;",
+    "}",
+    "let Map = false;"
+  ];
+
+  TestRun(test)
+    .addError(4, "Redefinition of 'Map'.")
+    .test(code, { esnext: true, browser: true });
+  test.done();
+};
+
 exports["test destructuring function as moz"] = function (test) {
   // Example from https://developer.mozilla.org/en-US/docs/JavaScript/New_in_JavaScript/1.7
   var code = [