remove more unused fonts

lib/single-file/fonts-minifier.js

@@ -29,7 +29,7 @@ this.fontsMinifier = this.fontsMinifier || (() => {
 	return {
 		process: (doc, secondPass) => {
 			const declaredFonts = new Set();
-			const usedFonts = new Set();
+			const usedFonts = [];
 			const stats = {
 				rules: {
 					processed: 0,
@@ -50,10 +50,12 @@ this.fontsMinifier = this.fontsMinifier || (() => {
 			});
 			doc.querySelectorAll("[style]").forEach(element => {
 				if (element.style.fontFamily) {
-					element.style.fontFamily.split(",").forEach(fontFamilyName => usedFonts.add(getFontFamilyName(fontFamilyName)));
+					const fontFamilyNames = element.style.fontFamily.split(",").map(fontFamilyName => getFontFamilyName(fontFamilyName));
+					usedFonts.push(fontFamilyNames);
 				}
 			});
-			const unusedFonts = Array.from(declaredFonts).filter(fontFamilyName => !usedFonts.has(fontFamilyName));
+			const filteredUsedFonts = new Set(usedFonts.map(fontNames => fontNames.find(fontName => declaredFonts.has(fontName))).filter(fontName => fontName));
+			const unusedFonts = Array.from(declaredFonts).filter(fontFamilyName => !filteredUsedFonts.has(fontFamilyName));
 			doc.querySelectorAll("style").forEach(style => {
 				if (style.sheet) {
 					const processedRules = style.sheet.cssRules.length;
@@ -75,7 +77,8 @@ this.fontsMinifier = this.fontsMinifier || (() => {
 					stylesheetContent += "}";
 				} else if (rule.type == CSSRule.STYLE_RULE) {
 					if (rule.style && rule.style.fontFamily) {
-						rule.style.fontFamily.split(",").forEach(fontFamilyName => usedFonts.add(getFontFamilyName(fontFamilyName)));
+						const fontFamilyNames = rule.style.fontFamily.split(",").map(fontFamilyName => getFontFamilyName(fontFamilyName));
+						usedFonts.push(fontFamilyNames);
 					}
 					stylesheetContent += rule.cssText;
 				} else {