callbcak function is called twice if a bind arror happens

[zhaotq@…]

The problem is in dojo.io.XMLHTTPTransport.bind. The following code starts from line 610.

		if(kwArgs.method.toLowerCase() == "post"){
			// FIXME: need to hack in more flexible Content-Type setting here!
			if (!kwArgs.user) {
				http.open("POST", url, async);
			}else{
        http.open("POST", url, async, kwArgs.user, kwArgs.password);
			}
			setHeaders(http, kwArgs);
			http.setRequestHeader("Content-Type", kwArgs.multipart ? ("multipart/form-data; boundary=" + this.multipartBoundary) : 
				(kwArgs.contentType || "application/x-www-form-urlencoded"));
			try{
				http.send(query);
			}catch(e){
				if(typeof http.abort == "function"){
					http.abort();
				}
				doLoad(kwArgs, {status: 404}, url, query, useCache);
			}
		}else{
			var tmpUrl = url;
			if(query != "") {
				tmpUrl += (tmpUrl.indexOf("?") > -1 ? "&" : "?") + query;
			}
			if(preventCache) {
				tmpUrl += (dojo.string.endsWithAny(tmpUrl, "?", "&")
					? "" : (tmpUrl.indexOf("?") > -1 ? "&" : "?")) + "dojo.preventCache=" + new Date().valueOf();
			}
			if (!kwArgs.user) {
				http.open(kwArgs.method.toUpperCase(), tmpUrl, async);
			}else{
				http.open(kwArgs.method.toUpperCase(), tmpUrl, async, kwArgs.user, kwArgs.password);
			}
			setHeaders(http, kwArgs);
			try {
				http.send(null);
			}catch(e)	{
				if(typeof http.abort == "function"){
					http.abort();
				}
				doLoad(kwArgs, {status: 404}, url, query, useCache);
			}
		}

Before the code, the inFlightTimer is set up. When the http.send throw an exception, the doLoad is called, but the inFlightTimer is not cancelled. So, the callback is called twice, one is in the catch block, on is from the inFlightTimer.

Proposed change:

in the catch block before calling the doLoad:

if (async) clearTimeout(this.inFlightTimer);

[James Burke]

This should be fixed in 1.0: the send call is wrapped in a try/catch, and the deferred.cancel is called if there is an error. In this case, the inflight checks will do nothing more, just remove it from the inflight queue.