requireVarDeclFirst: be aware of the comments

In this edge case the comments from previous block scope were being taken and
a false positive error was thrown

Fixes #2022
Closes gh-2061

Author: kepta

lib/rules/require-var-decl-first.js

@@ -180,6 +180,14 @@ function getCommentOffsetBetweenNodes(previousNode, currentNode, commentTokens,
             break;
         }
 
+        if (previousNode.range[1] < currentNode.range[0] &&
+            comment.range[0] > previousNode.range[0] &&
+            comment.range[1] < previousNode.range[1]) {
+            // Stop processing comments that are within multiple declarators in a single variable declaration
+            // of the previous node and the previousNode is not the parent of currentNode
+            break;
+        }
+
         if (comment.range[0] > currentNode.range[0] &&
             comment.range[1] < currentNode.range[1]) {
             // Stop processing comments that are within multiple declarators in a single variable declaration

test/specs/rules/require-var-decl-first.js

@@ -233,6 +233,11 @@ describe('rules/require-var-decl-first', function() {
                     testDeclStatements(checker,
                         'function tst(node) {\nvar array,\n/* array of class names */\nncn = node.className;\n}', 0);
                 });
+
+                it('should not return errors for multiple var declaration with a comment inside the scope of' +
+                ' first variable declaration', function() {
+                    testDeclStatements(checker, 'var a = function() {  var b;\n/*block comment*/\n};\nvar c;', 0);
+                });
             });
         });
     });