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

Author: jeresig

src/core.js

@@ -480,6 +480,9 @@ jQuery.extend({
 		if ( typeof data !== "string" || !data ) {
 			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

test/unit/core.js

@@ -807,14 +807,16 @@ 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." );
 	equals( jQuery.parseJSON( "" ), null, "Nothing in, null out." );
 
 	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}");
@@ -829,4 +831,4 @@ test("jQuery.parseJSON", function(){
 	} catch( e ) {
 		ok( true, "Test malformed JSON string." );
 	}
-});
+});