Reworks how values of parameters passed to error callbacks are determined. Fixes #8050.

src/ajax.js

@@ -400,8 +400,9 @@ jQuery.extend({
 
 				// Cancel the request
 				abort: function( statusText ) {
+					statusText = statusText || "abort";
 					if ( transport ) {
-						transport.abort( statusText || "abort" );
+						transport.abort( statusText );
 					}
 					done( 0, statusText );
 					return this;
@@ -438,7 +439,7 @@ jQuery.extend({
 
 			var isSuccess,
 				success,
-				error = ( statusText = statusText || "error" ),
+				error,
 				response = responses ? ajaxHandleResponses( s, jXHR, responses ) : undefined,
 				lastModified,
 				etag;
@@ -476,6 +477,16 @@ jQuery.extend({
 						error = "" + e;
 					}
 				}
+			} else {
+				// We extract error from statusText
+				// then normalize statusText and status for non-aborts
+				error = statusText;
+				if( status ) {
+					statusText = "error";
+					if ( status < 0 ) {
+						status = 0;
+					}
+				}
 			}
 
 			// Set data for the fake xhr object
@@ -634,7 +645,7 @@ jQuery.extend({
 
 			// If no transport, we auto-abort
 			if ( !transport ) {
-				done( 0, "notransport" );
+				done( -1, "No Transport" );
 			} else {
 				// Set state as sending
 				state = jXHR.readyState = 1;
@@ -653,9 +664,8 @@ jQuery.extend({
 					transport.send( requestHeaders, done );
 				} catch (e) {
 					// Propagate exception as error if not done
-					if ( status === 1 ) {
-						done( 0, "error", "" + e );
-						jXHR = false;
+					if ( status < 2 ) {
+						done( -1, "" + e );
 					// Simply rethrow otherwise
 					} else {
 						jQuery.error( e );

src/ajax/xhr.js

@@ -108,12 +108,9 @@ if ( jQuery.support.ajax ) {
 					} catch( _ ) {}
 
 					// Do send the request
-					try {
-						xhr.send( ( s.hasContent && s.data ) || null );
-					} catch( e ) {
-						complete( 0, "error", "" + e );
-						return;
-					}
+					// This may raise an exception which is actually
+					// handled in jQuery.ajax (so no try/catch here)
+					xhr.send( ( s.hasContent && s.data ) || null );
 
 					// Listener
 					callback = function( _, isAbort ) {