fix escaping of special characters (issue zaach#22)

Author: zaach

lib/jsonlint.js

@@ -9,7 +9,15 @@ performAction: function anonymous(yytext,yyleng,yylineno,yy,yystate,$$,_$) {
 
 var $0 = $$.length - 1;
 switch (yystate) {
-case 1:this.$ = yytext.replace(/\\\\/g, "\\");
+case 1: // replace escaped characters with actual character
+          this.$ = yytext.replace(/\\(\\|")/g, "$"+"1")
+                     .replace(/\\n/g,'\n')
+                     .replace(/\\r/g,'\r')
+                     .replace(/\\t/g,'\t')
+                     .replace(/\\v/g,'\v')
+                     .replace(/\\f/g,'\f')
+                     .replace(/\\b/g,'\b');
+        
 break;
 case 2:this.$ = Number(yytext);
 break;
@@ -367,13 +375,13 @@ var YYSTATE=YY_START
 switch($avoiding_name_collisions) {
 case 0:/* skip whitespace */
 break;
-case 1:return 6;
+case 1:return 6
 break;
-case 2:yy_.yytext = yy_.yytext.substr(1,yy_.yyleng-2); return 4;
+case 2:yy_.yytext = yy_.yytext.substr(1,yy_.yyleng-2); return 4
 break;
-case 3: return 17 
+case 3:return 17
 break;
-case 4: return 18 
+case 4:return 18
 break;
 case 5:return 23
 break;

src/jsonlint.l

@@ -9,7 +9,7 @@ frac  "."[0-9]+
 \"(?:'\\'[\\"bfnrt/]|'\\u'[a-fA-F0-9]{4}|[^\\\0-\x09\x0a-\x1f"])*\"    yytext = yytext.substr(1,yyleng-2); return 'STRING'
 
 "{"      return '{'
-"}"      return ''
+"}"      return '}'
 "["      return '['
 "]"      return ']'
 ","      return ','

src/jsonlint.y

@@ -9,7 +9,15 @@
 
 JSONString
     : STRING
-        {$$ = yytext.replace(/\\\\/g, "\\");}
+        { // replace escaped characters with actual character
+          $$ = yytext.replace(/\\(\\|")/g, "$"+"1")
+                     .replace(/\\n/g,'\n')
+                     .replace(/\\r/g,'\r')
+                     .replace(/\\t/g,'\t')
+                     .replace(/\\v/g,'\v')
+                     .replace(/\\f/g,'\f')
+                     .replace(/\\b/g,'\b');
+        }
     ;
 
 JSONNumber

test/all-tests.js

@@ -12,9 +12,20 @@ exports["test escaped backslash"] = function () {
     assert.deepEqual(parser.parse(json), {"foo": "\\"});
 };
 
+exports["test escaped chars"] = function () {
+    var json = '{"foo": "\\\\\\\""}';
+    assert.deepEqual(parser.parse(json), {"foo": '\\\"'});
+};
+
+exports["test escaped \\n"] = function () {
+    var json = '{"foo": "\\\\\\n"}';
+    assert.deepEqual(parser.parse(json), {"foo": '\\\n'});
+};
+
 exports["test string with escaped line break"] = function () {
     var json = '{"foo": "bar\\nbar"}';
-    assert.deepEqual(parser.parse(json), {"foo": "bar\\nbar"});
+    assert.deepEqual(parser.parse(json), {"foo": "bar\nbar"});
+    assert.equal(JSON.stringify(parser.parse(json)).length, 18);
 };
 
 exports["test string with line break"] = function () {