Make sure leading whitespace is trimmed for parseJSON. Fixes #6031.

src/core.js

@@ -481,6 +481,9 @@ jQuery.extend({
 			return null;
 		}
 
+		// Make sure leading/trailing whitespace is removed (IE can't handle it)
+		data = jQuery.trim( data );
+		
 		// Make sure the incoming data is actual JSON
 		// Logic borrowed from http://json.org/json2.js
 		if ( /^[\],:{}\s]*$/.test(data.replace(/\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g, "@")

test/unit/core.js

@@ -807,7 +807,7 @@ test("jQuery.proxy", function(){
 });
 
 test("jQuery.parseJSON", function(){
-	expect(7);
+	expect(8);
 	
 	equals( jQuery.parseJSON(), null, "Nothing in, null out." );
 	equals( jQuery.parseJSON( null ), null, "Nothing in, null out." );
@@ -816,6 +816,8 @@ test("jQuery.parseJSON", function(){
 	same( jQuery.parseJSON("{}"), {}, "Plain object parsing." );
 	same( jQuery.parseJSON('{"test":1}'), {"test":1}, "Plain object parsing." );
 
+	same( jQuery.parseJSON('\n{"test":1}'), {"test":1}, "Make sure leading whitespaces are handled." );
+	
 	try {
 		jQuery.parseJSON("{a:1}");
 		ok( false, "Test malformed JSON string." );