rhash = /#.*$/,
        rheaders = /^(.*?):\s*(.*?)\r?$/mg, // IE leaves an \r character at EOL
        rinput = /^(?:color|date|datetime|email|hidden|month|number|password|range|search|tel|text|time|url|week)$/i,
+       // #8125, #8152: local protocol detection
+       rlocalProtocol = /^(file|chrome\-extension):$/,
        rnoContent = /^(?:GET|HEAD)$/,
        rprotocol = /^\/\//,
        rquery = /\?/,
         */
        transports = {},
 
-       // Stored document location array
-       ajaxLocation;
+       // Document location
+       ajaxLocation,
+
+       // Document location segments
+       ajaxLocParts;
 
 // #8138, IE may throw an exception when accessing
 // a field from document.location if document.domain has been set
        ajaxLocation = ajaxLocation.href;
 }
 
+// Segment location into parts
+ajaxLocParts = rurl.exec( ajaxLocation.toLowerCase() );
+
 // Base "constructor" for jQuery.ajaxPrefilter and jQuery.ajaxTransport
 function addToPrefiltersOrTransports( structure ) {
 
 
        ajaxSettings: {
                url: ajaxLocation,
+               isLocal: rlocalProtocol.test( ajaxLocParts[ 1 ] ),
                global: true,
                type: "GET",
                contentType: "application/x-www-form-urlencoded",
                // Remove hash character (#7531: and string promotion)
                // Add protocol if not provided (#5866: IE7 issue with protocol-less urls)
                // We also use the url parameter if available
-               s.url = ( "" + ( url || s.url ) ).replace( rhash, "" ).replace( rprotocol, ajaxLocation[ 1 ] + "//" );
+               s.url = ( "" + ( url || s.url ) ).replace( rhash, "" ).replace( rprotocol, ajaxLocParts[ 1 ] + "//" );
 
                // Extract dataTypes list
                s.dataTypes = jQuery.trim( s.dataType || "*" ).toLowerCase().split( rspacesAjax );
                if ( !s.crossDomain ) {
                        parts = rurl.exec( s.url.toLowerCase() );
                        s.crossDomain = !!( parts &&
-                               ( parts[ 1 ] != ajaxLocation[ 1 ] || parts[ 2 ] != ajaxLocation[ 2 ] ||
+                               ( parts[ 1 ] != ajaxLocParts[ 1 ] || parts[ 2 ] != ajaxLocParts[ 2 ] ||
                                        ( parts[ 3 ] || ( parts[ 1 ] === "http:" ? 80 : 443 ) ) !=
-                                               ( ajaxLocation[ 3 ] || ( ajaxLocation[ 1 ] === "http:" ? 80 : 443 ) ) )
+                                               ( ajaxLocParts[ 3 ] || ( ajaxLocParts[ 1 ] === "http:" ? 80 : 443 ) ) )
                        );
                }
 
        }
 });
 
-// Segment ajaxLocation into parts
-ajaxLocation = rurl.exec( ajaxLocation.toLowerCase() );
-
 function buildParams( prefix, obj, traditional, add ) {
        if ( jQuery.isArray( obj ) && obj.length ) {
                // Serialize array item.
 
         * we need a fallback.
         */
        function() {
-               if ( window.location.protocol !== "file:" ) {
+               if ( !jQuery.ajaxSettings.isLocal ) {
                        try {
                                return new window.XMLHttpRequest();
                        } catch( xhrError ) {}
                                                                        }
 
                                                                        // Filter status for non standard behaviors
-                                                                       status =
-                                                                               // Most browsers return 0 when it should be 200 for local files
-                                                                               // Opera returns 0 when it should be 304
-                                                                               // Webkit returns 0 for failing cross-domain no matter the real status
-                                                                               !status ?
-                                                                                       // All: for local files, 0 is a success
-                                                                                       ( location.protocol === "file:" ? 200 : (
-                                                                                               // Webkit, Firefox: filter out faulty cross-domain requests
-                                                                                               !s.crossDomain || statusText ?
-                                                                                               (
-                                                                                                       // Opera: filter out real aborts #6060
-                                                                                                       responseHeaders ?
-                                                                                                       304 :
-                                                                                                       0
-                                                                                               ) :
-                                                                                               // We assume 302 but could be anything cross-domain related
-                                                                                               302
-                                                                                       ) ) :
-                                                                                       (
-                                                                                               // IE sometimes returns 1223 when it should be 204 (see #1450)
-                                                                                               status == 1223 ?
-                                                                                                       204 :
-                                                                                                       status
-                                                                                       );
+
+                                                                       // IE - #1450: sometimes returns 1223 when it should be 204
+                                                                       if ( status === 1223 ) {
+                                                                               status = 204;
+                                                                       // Status 0 encompasses several cases
+                                                                       } else if ( !status ) {
+                                                                               // Cross-domain
+                                                                               if ( s.crossDomain ) {
+                                                                                       if ( !s.statusText ) {
+                                                                                               // FF, Webkit (other?): There is no status text for errors
+                                                                                               // 302 is the most generic cross-domain status code
+                                                                                               // for errors, could be anything really (even a real 0)
+                                                                                               status = 302;
+                                                                                       }
+                                                                               // All same-domain - #8125, #8152: for local files, 0 is a success
+                                                                               } else if( s.isLocal ) {
+                                                                                       status = 200;
+                                                                               }
+                                                                               // Opera - #6060: sets status as 0 for 304
+                                                                               // and there doesn't seem to be any way to
+                                                                               // detect this case. Patch VERY welcome.
+                                                                       }
                                                                }
                                                        }
                                                } catch( firefoxAccessException ) {