When you use headers to set the "Content-Type" header for a request, this breaks in Safari. jQuery parses the dataType parameter and sets the "Content-Type" header once, which usually is fine, but if I try and manually set "Content-Type" header in the beforeSend method, Safari combines the default with the header I set:

jQuery.ajax({

url: 'foos.json',

data: myJsonString,

beforeSend: function(xhr) {

xhr.setRequestHeader("Content-Type","application/json");

},

success: function(data) {

//do something

}

});

In Safari, because jQuery defaults "Content-Type" to "application/x-www-form-urlencoded", the text of the "Content-Type" header is set to

"Content-Type": "application/x-www-form-urlencoded, application/json"

Which obviously does not work. Really Safari should just overwrite the header's content when it is reset, but it does not. The workaround is of course to just use the contentType parameter to $.ajax, but I should technically be able to set the header and have the same behavior.