Fix #11743: Don't mask script errors in jQuery.ajax, closes gh-795.

src/ajax.js

@@ -319,6 +319,7 @@ jQuery.extend({
 		username: null,
 		password: null,
 		cache: null,
+		throws: false,
 		traditional: false,
 		headers: {},
 		*/
@@ -480,6 +481,8 @@ jQuery.extend({
 		// It is defined here because jslint complains if it is declared
 		// at the end of the function (which would be more logical and readable)
 		function done( status, nativeStatusText, responses, headers ) {
+			var isSuccess, success, error, response, modified,
+				statusText = nativeStatusText;
 
 			// Called once
 			if ( state === 2 ) {
@@ -504,25 +507,24 @@ jQuery.extend({
 			// Set readyState
 			jqXHR.readyState = status > 0 ? 4 : 0;
 
-			var isSuccess,
-				success,
-				error,
-				statusText = nativeStatusText,
-				response = responses ? ajaxHandleResponses( s, jqXHR, responses ) : undefined,
-				lastModified,
-				etag;
+			// Get response data
+			if ( responses ) {
+				response = ajaxHandleResponses( s, jqXHR, responses );
+			}
 
 			// If successful, handle type chaining
 			if ( status >= 200 && status < 300 || status === 304 ) {
 
 				// Set the If-Modified-Since and/or If-None-Match header, if in ifModified mode.
 				if ( s.ifModified ) {
 
-					if ( ( lastModified = jqXHR.getResponseHeader( "Last-Modified" ) ) ) {
-						jQuery.lastModified[ ifModifiedKey ] = lastModified;
+					modified = jqXHR.getResponseHeader("Last-Modified");
+					if ( modified ) {
+						jQuery.lastModified[ ifModifiedKey ] = modified;
 					}
-					if ( ( etag = jqXHR.getResponseHeader( "Etag" ) ) ) {
-						jQuery.etag[ ifModifiedKey ] = etag;
+					modified = jqXHR.getResponseHeader("Etag");
+					if ( modified ) {
+						jQuery.etag[ ifModifiedKey ] = modified;
 					}
 				}
 
@@ -535,15 +537,11 @@ jQuery.extend({
 				// If we have data
 				} else {
 
-					try {
-						success = ajaxConvert( s, response );
-						statusText = "success";
-						isSuccess = true;
-					} catch(e) {
-						// We have a parsererror
-						statusText = "parsererror";
-						error = e;
-					}
+					isSuccess = ajaxConvert( s, response );
+					statusText = isSuccess.state;
+					success = isSuccess.data;
+					error = isSuccess.error;
+					isSuccess = !error;
 				}
 			} else {
 				// We extract error from statusText
@@ -913,86 +911,87 @@ function ajaxHandleResponses( s, jqXHR, responses ) {
 // Chain conversions given the request and the original response
 function ajaxConvert( s, response ) {
 
+	var conv, conv2, current, tmp,
+		// Work with a copy of dataTypes in case we need to modify it for conversion
+		dataTypes = s.dataTypes.slice(),
+		prev = dataTypes[ 0 ],
+		converters = {},
+		i = 0;
+
 	// Apply the dataFilter if provided
 	if ( s.dataFilter ) {
 		response = s.dataFilter( response, s.dataType );
 	}
 
-	var dataTypes = s.dataTypes,
-		converters = {},
-		i,
-		key,
-		length = dataTypes.length,
-		tmp,
-		// Current and previous dataTypes
-		current = dataTypes[ 0 ],
-		prev,
-		// Conversion expression
-		conversion,
-		// Conversion function
-		conv,
-		// Conversion functions (transitive conversion)
-		conv1,
-		conv2;
-
-	// For each dataType in the chain
-	for ( i = 1; i < length; i++ ) {
-
-		// Create converters map
-		// with lowercased keys
-		if ( i === 1 ) {
-			for ( key in s.converters ) {
-				if ( typeof key === "string" ) {
-					converters[ key.toLowerCase() ] = s.converters[ key ];
-				}
-			}
+	// Create converters map with lowercased keys
+	if ( dataTypes[ 1 ] ) {
+		for ( conv in s.converters ) {
+			converters[ conv.toLowerCase() ] = s.converters[ conv ];
 		}
+	}
+
+	// Convert to each sequential dataType, tolerating list modification
+	for ( ; (current = dataTypes[++i]); ) {
+
+		// There's only work to do if current dataType is non-auto
+		if ( current !== "*" ) {
+
+			// Convert response if prev dataType is non-auto and differs from current
+			if ( prev !== "*" && prev !== current ) {
+
+				// Seek a direct converter
+				conv = converters[ prev + " " + current ] || converters[ "* " + current ];
 
-		// Get the dataTypes
-		prev = current;
-		current = dataTypes[ i ];
-
-		// If current is auto dataType, update it to prev
-		if ( current === "*" ) {
-			current = prev;
-		// If no auto and dataTypes are actually different
-		} else if ( prev !== "*" && prev !== current ) {
-
-			// Get the converter
-			conversion = prev + " " + current;
-			conv = converters[ conversion ] || converters[ "* " + current ];
-
-			// If there is no direct converter, search transitively
-			if ( !conv ) {
-				conv2 = undefined;
-				for ( conv1 in converters ) {
-					tmp = conv1.split( " " );
-					if ( tmp[ 0 ] === prev || tmp[ 0 ] === "*" ) {
-						conv2 = converters[ tmp[1] + " " + current ];
-						if ( conv2 ) {
-							conv1 = converters[ conv1 ];
-							if ( conv1 === true ) {
-								conv = conv2;
-							} else if ( conv2 === true ) {
-								conv = conv1;
+				// If none found, seek a pair
+				if ( !conv ) {
+					for ( conv2 in converters ) {
+
+						// If conv2 outputs current
+						tmp = conv2.split(" ");
+						if ( tmp[ 1 ] === current ) {
+
+							// If prev can be converted to accepted input
+							conv = converters[ prev + " " + tmp[ 0 ] ] ||
+								converters[ "* " + tmp[ 0 ] ];
+							if ( conv ) {
+								// Condense equivalence converters
+								if ( conv === true ) {
+									conv = converters[ conv2 ];
+
+								// Otherwise, insert the intermediate dataType
+								} else if ( converters[ conv2 ] !== true ) {
+									current = tmp[ 0 ];
+									dataTypes.splice( i--, 0, current );
+								}
+
+								break;
 							}
-							break;
+						}
+					}
+				}
+
+				// Apply converter (if not an equivalence)
+				if ( conv !== true ) {
+
+					// Unless errors are allowed to bubble, catch and return them
+					if ( conv && s.throws ) {
+						response = conv( response );
+					} else {
+						try {
+							response = conv( response );
+						} catch ( e ) {
+							return { state: "parsererror", error: conv ? e : "No conversion from " + prev + " to " + current };
 						}
 					}
 				}
 			}
-			// If we found no converter, dispatch an error
-			if ( !( conv || conv2 ) ) {
-				jQuery.error( "No conversion from " + conversion.replace(" "," to ") );
-			}
-			// If found converter is not an equivalence
-			if ( conv !== true ) {
-				// Convert with 1 or 2 converters accordingly
-				response = conv ? conv( response ) : conv2( conv1(response) );
-			}
+
+			// Update prev for next iteration
+			prev = current;
 		}
 	}
-	return response;
+
+	return { state: "success", data: response };
 }
 
 })( jQuery );

src/manipulation.js

@@ -343,11 +343,12 @@ jQuery.fn.extend({
 				jQuery.each( scripts, function( i, elem ) {
 					if ( elem.src ) {
 						jQuery.ajax({
-							type: "GET",
-							global: false,
 							url: elem.src,
+							type: "GET",
+							dataType: "script",
 							async: false,
-							dataType: "script"
+							global: false,
+							throws: true
 						});
 					} else {
 						jQuery.globalEval( ( elem.text || elem.textContent || elem.innerHTML || "" ).replace( rcleanScript, "" ) );

test/data/badjson.js

@@ -1 +1 @@
-{bad: 1}
+{bad: toTheBone}

test/unit/ajax.js

@@ -1746,6 +1746,28 @@ test("jQuery.ajax() - malformed JSON", function() {
 	});
 });
 
+test("jQuery.ajax() - script, throws exception (#11743)", function() {
+	expect(1);
+
+	raises(function() {
+		jQuery.ajax({
+			url: "data/badjson.js",
+			dataType: "script",
+			throws: true,
+			// TODO find a way to test this asynchronously, too
+			async: false,
+			// Global events get confused by the exception
+			global: false,
+			success: function() {
+				ok( false, "Success." );
+			},
+			error: function() {
+				ok( false, "Error." );
+			}
+		});
+	}, "exception bubbled" );
+});
+
 test("jQuery.ajax() - script by content-type", function() {
 	expect(2);
 

test/unit/manipulation.js

@@ -1796,3 +1796,17 @@ test("Ensure oldIE creates a new set on appendTo (#8894)", function() {
 	strictEqual( jQuery("<bdi/>").clone().addClass("test").appendTo("<div/>").end().hasClass("test"), false, "Check jQuery.fn.appendTo after clone html5 element" );
 	strictEqual( jQuery("<p/>").appendTo("<div/>").end().length, jQuery("<p>test</p>").appendTo("<div/>").end().length, "Elements created with createElement and with createDocumentFragment should be treated alike" );
 });
+
+test("html() - script exceptions bubble (#11743)", function() {
+	expect(2);
+
+	raises(function() {
+		jQuery("#qunit-fixture").html("<script>undefined(); ok( false, 'error not thrown' );</script>");
+		ok( false, "error ignored" );
+	}, "exception bubbled from inline script" );
+
+	raises(function() {
+		jQuery("#qunit-fixture").html("<script src='data/badjson.js'></script>");
+		ok( false, "error ignored" );
+	}, "exception bubbled from remote script" );
+});