I'm seeing an odd behavior in WebKit (on Android) where my server process is sending it a response that it needs to handle immediately (rather than wait for readyState 4). In Firefox and Safari this works as expected, but on webkit, not only does it not respond to the readyState but instead it appears to fire off a repeat request to the server!
This only seems to happen when the server takes a little while to react to the request. I'm still poking around to see what the exact circumstances are that bring this about, but am curious if this is a known bug and what, if anything, is a workaround.
[EDIT] This is just getting weirder and weirder. As long as the server responds within about 10 seconds, everything is fine. But if it takes longer than that, then the request is resubmitted. However, the browser appears to not be aware of this re-submission, or if it is, it's not reporting it in any way. I attached a unique ID to the request and when it arrives for the second time on the server the id is the same. But it's definitely spawning off an additional call to the server. I'm sort of at a loss as to how to debug this further.
[EDIT 2] No one has piped in, so. I have fixed the problem by killing the connection from the server side.
So, my solution:
a) client makes call to server (which is a perl.cgi)
b) server code:
print (some JSON for the broswer);
close(STDOUT); #this sends a readyState 4 to the browser and closes the connection.
&methodThatTakesAWhile();
This doesn't explain WHY the browser is misbehaving, but it does get around this particular bug.