#292 don't duplicate querystring parameters if dataType and method are both present

mithril.js

@@ -872,7 +872,7 @@ Mithril = m = new function app(window, undefined) {
 	}
 	function bindData(xhrOptions, data, serialize) {
 		if (data && Object.keys(data).length > 0) {
-			if (xhrOptions.method == "GET") {
+			if (xhrOptions.method == "GET" && xhrOptions.dataType != "jsonp") {
 				xhrOptions.url = xhrOptions.url + (xhrOptions.url.indexOf("?") < 0 ? "?" : "&") + buildQueryString(data)
 			}
 			else xhrOptions.data = serialize(data)

tests/mithril-tests.js

@@ -1761,6 +1761,39 @@ function testMithril(mock) {
 		mock.document.removeChild(body);
 		return correctData;
 	})
+	test(function(){
+		var body = mock.document.createElement("body");
+		mock.document.body = body;
+		mock.document.appendChild(body);
+
+		var _window = mock;
+		var error = m.prop(false);
+		var req = m.request({
+			url: "/test",
+			dataType: "jsonp",
+			method: "GET",
+			data: { foo: "bar" },
+			background: true
+		});
+		var callbackKeys = [];
+		Object.keys(_window).forEach(function(globalKey){
+			if(globalKey.indexOf("mithril_callback") > -1)
+				callbackKeys.push(globalKey);
+		});
+		var scriptTag = null;
+		mock.document.getElementsByTagName("script").forEach(function(script){
+			if(!scriptTag && script.src.indexOf(callbackKeys[0]) > -1)
+				scriptTag = script;
+		});
+		var correctData = false;
+		if(scriptTag){
+			correctData = scriptTag.src.match(/foo=bar/g).length == 1;
+			mock.document.body.removeChild(scriptTag);
+			delete _window[callbackKeys[0]];
+		}
+		mock.document.removeChild(body);
+		return correctData;
+	})
 
 	//m.deferred
 	test(function() {