fix parsing of svg images

lib/single-file/single-file-core.js

@@ -1911,8 +1911,8 @@ class ProcessorHelper {
 				if (testValidURL(resourceURL)) {
 					let svgDoc;
 					if (!originalResourceURL.startsWith(baseURI + "#")) {
-						const content = await batchRequest.addURL(resourceURL);
-						svgDoc = util.parseSVGContent(content);
+						const response = await batchRequest.addURL(resourceURL);
+						svgDoc = util.parseSVGContent(response.content);
 					} else {
 						svgDoc = doc;
 					}

lib/single-file/single-file-util.js

@@ -97,6 +97,8 @@ function getInstance(utilOptions) {
 			const doc = (new DOMParser()).parseFromString(content, "image/svg+xml");
 			if (doc.querySelector("parsererror")) {
 				return (new DOMParser()).parseFromString(content, "text/html");
+			} else {
+				return doc;
 			}
 		},
 		async digest(algo, text) {