don't transform to svg sprites images with padding or margin

lib/single-file/doc-helper.js

@@ -18,7 +18,7 @@
  *   along with SingleFile.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-/* global fontFaceProxy */
+/* global fontFaceProxy, getComputedStyle */
 
 this.docHelper = this.docHelper || (() => {
 
@@ -161,7 +161,10 @@ this.docHelper = this.docHelper || (() => {
 			doc.querySelectorAll("img[src]").forEach((imageElement, imageElementIndex) => {
 				imageElement.setAttribute(imagesAttributeName(options.sessionId), imageElementIndex);
 				let imageData;
-				if (imageElement.src) {
+				const computedStyle = getComputedStyle(imageElement);
+				const paddingIsSet = computedStyle.padding != "0px";
+				const marginIsSet = computedStyle.margin != "0px";
+				if (imageElement.src && !paddingIsSet && !marginIsSet) {
 					let naturalWidth = imageElement.naturalWidth;
 					let naturalHeight = imageElement.naturalHeight;
 					if (naturalWidth <= 1 && naturalHeight <= 1) {
@@ -172,24 +175,8 @@ this.docHelper = this.docHelper || (() => {
 						naturalHeight = imgElement.height;
 						imgElement.remove();
 					}
-					const marginValue = imageElement.style.getPropertyValue("margin");
-					const marginPriority = imageElement.style.getPropertyPriority("margin");
-					const paddingValue = imageElement.style.getPropertyValue("padding");
-					const paddingPriority = imageElement.style.getPropertyPriority("padding");
-					imageElement.style.setProperty("margin", "0", "important");
-					imageElement.style.setProperty("padding", "0", "important");
 					const clientWidth = imageElement.clientWidth;
 					const clientHeight = imageElement.clientHeight;
-					if (marginValue || marginPriority) {
-						imageElement.style.setProperty("margin", marginValue, marginPriority);
-					} else {
-						imageElement.style.removeProperty("margin");
-					}
-					if (paddingValue || paddingPriority) {
-						imageElement.style.setProperty("padding", paddingValue, paddingPriority);
-					} else {
-						imageElement.style.removeProperty("padding");
-					}
 					imageData = {
 						width: imageElement.width,
 						height: imageElement.height,
@@ -198,6 +185,8 @@ this.docHelper = this.docHelper || (() => {
 						naturalWidth,
 						naturalHeight
 					};
+				} else {
+					imageData = {};
 				}
 				data.push(imageData);
 			});