I found this behaviour of $.ajax using this simple code. I tested this on Firefox, Chrome and Safari (not on IE :| ). I'm using jQuery 1.4.2

Suppose you have this code:

2. function test() {
3. $.ajax( {
4. url : 'test/GameConfiguration.json',
5. dataType : 'json',
6. data : {
7. a : 'aaa'
8. },
9. cache : false,
10. method : 'get',
11. timeout : 10000, //10 secs of timeout 
12. success : function(data, textStatus, XMLHttpRequest) {
13. console.log("success");
14. if (data == null)
15. console.log("it's not a real success");
16. },
17. error : function(XMLHttpRequest, textStatus, errorThrown) {
18. console.log("error: " + textStatus);
19. }
20. });
21. }

What this function does is pretty obvious. I created a page with a button that has onclick="test()", but I found this bahaviour even in other situations. 

Here is the problem: I load the page from an Apache webserver on localhost (a standard Wamp install). Then before clicking the button I shut the server off. When I click the button that fires test() it happens that:

• The request doesn't take 10 seconds to complete, but fires early
• The success handler will be called, but the data argument is set to null.

Anyway if I use my collegue PC to do the test and I do it this way:

1. I load the page on his computer from my webserver
2. Before calling test I DISCONNECT my computer from the network
3. I press the button that fires test()

I'm happy that this works as expected on real world conditions, but I'd like to test a more complex functionality locally (ajax apps are not always this simple :))

At least I thinks you should document this behaviour on the API reference.

Cheers