Bugfix: new CSS <style> removing (background-)?color failed

dev/Common/CSS.js

@@ -1,84 +0,0 @@
-
-export class CSS
-{
-	/*
-		Parses given css string, and returns css object
-		keys as selectors and values are css rules
-		eliminates all css comments before parsing
-
-		@param source css string to be parsed
-
-		@return object css
-	*/
-	parse(source) {
-
-		const css = [];
-
-		css.toString = () => css.reduce(
-			(ret, tmp) =>
-				ret + tmp.selector + ' {\n'
-					+ (tmp.type === 'media' ? tmp.subStyles.toString() : tmp.rules)
-					+ '}\n'
-			,
-			''
-		);
-
-		/**
-		 * Given css array, parses it and then for every selector,
-		 * prepends namespace to prevent css collision issues
-		 */
-		css.applyNamespace = (namespace, prefix) => css.forEach(obj => {
-			if (obj.type === 'media') {
-				obj.subStyles.applyNamespace(namespace, prefix);
-			} else {
-				obj.selector = obj.selector.split(',').map(selector =>
-					namespace + ' ' + selector.replace('.', '.'+prefix)
-				).join(',');
-			}
-		});
-
-		if (source) {
-			source = source
-				// strip comments
-				.replace(/\/\*[\s\S]*?\*\/|<!--|-->/gi, '')
-				// strip import statements
-				.replace(/@import .*?;/gi , '')
-				// strip keyframe statements
-				.replace(/((@.*?keyframes [\s\S]*?){([\s\S]*?}\s*?)})/gi, '');
-
-			// unified regex to match css & media queries together
-			let unified = /((\s*?(?:\/\*[\s\S]*?\*\/)?\s*?@media[\s\S]*?){([\s\S]*?)}\s*?})|(([\s\S]*?){([\s\S]*?)})/gi,
-				arr;
-
-			while (true) {
-				arr = unified.exec(source);
-				if (arr === null) {
-					break;
-				}
-
-				let selector = arr[arr[2] === undefined ? 5 : 2].split('\r\n').join('\n').trim()
-					// Never have more than a single line break in a row
-					.replace(/\n+/, "\n");
-
-				// determine the type
-				if (selector.includes('@media')) {
-					// we have a media query
-					css.push({
-						selector: selector,
-						type: 'media',
-						subStyles: this.parse(arr[3] + '\n}') //recursively parse media query inner css
-					});
-				} else if (!selector.includes('@') && ![':root','html','body'].includes(selector)) {
-					// we have standard css
-					css.push({
-						selector: selector,
-						rules: arr[6]
-					});
-				}
-			}
-		}
-
-		return css;
-	}
-
-}

dev/Common/Html.js

@@ -1,5 +1,4 @@
 import { createElement } from 'Common/Globals';
-import { CSS } from 'Common/CSS';
 import { forEachObjectEntry, pInt } from 'Common/Utils';
 import { SettingsUserStore } from 'Stores/User/Settings';
 
@@ -89,6 +88,83 @@ const
 			});
 		}
 		return url;
+	},
+
+	/*
+		Parses given css string, and returns css object
+		keys as selectors and values are css rules
+		eliminates all css comments before parsing
+
+		@param source css string to be parsed
+
+		@return object css
+	*/
+	parseCSS = source => {
+		const css = [];
+		css.toString = () => css.reduce(
+			(ret, tmp) =>
+				ret + tmp.selector + ' {\n'
+					+ (tmp.type === 'media' ? tmp.subStyles.toString() : tmp.rules)
+					+ '}\n'
+			,
+			''
+		);
+		/**
+		 * Given css array, parses it and then for every selector,
+		 * prepends namespace to prevent css collision issues
+		 */
+		css.applyNamespace = (namespace, prefix) => css.forEach(obj => {
+			if (obj.type === 'media') {
+				obj.subStyles.applyNamespace(namespace, prefix);
+			} else {
+				obj.selector = obj.selector.split(',').map(selector =>
+					namespace + ' ' + selector.replace('.', '.'+prefix)
+				).join(',');
+			}
+		});
+
+		if (source) {
+			source = source
+				// strip comments
+				.replace(/\/\*[\s\S]*?\*\/|<!--|-->/gi, '')
+				// strip import statements
+				.replace(/@import .*?;/gi , '')
+				// strip keyframe statements
+				.replace(/((@.*?keyframes [\s\S]*?){([\s\S]*?}\s*?)})/gi, '');
+
+			// unified regex to match css & media queries together
+			let unified = /((\s*?(?:\/\*[\s\S]*?\*\/)?\s*?@media[\s\S]*?){([\s\S]*?)}\s*?})|(([\s\S]*?){([\s\S]*?)})/gi,
+				arr;
+
+			while (true) {
+				arr = unified.exec(source);
+				if (arr === null) {
+					break;
+				}
+
+				let selector = arr[arr[2] === undefined ? 5 : 2].split('\r\n').join('\n').trim()
+					// Never have more than a single line break in a row
+					.replace(/\n+/, "\n");
+
+				// determine the type
+				if (selector.includes('@media')) {
+					// we have a media query
+					css.push({
+						selector: selector,
+						type: 'media',
+						subStyles: parseCSS(arr[3] + '\n}') //recursively parse media query inner css
+					});
+				} else if (!selector.includes('@') && ![':root','html','body'].includes(selector)) {
+					// we have standard css
+					css.push({
+						selector: selector,
+						rules: arr[6]
+					});
+				}
+			}
+		}
+
+		return css;
 	};
 
 export const
@@ -209,13 +285,14 @@ export const
 				oStyle = oElement.style;
 
 			if ('STYLE' === name) {
-				if (msgId) {
-					let css = new CSS().parse(oElement.textContent);
+				let css = msgId ? parseCSS(oElement.textContent) : [];
+				if (css.length) {
 					css.applyNamespace(msgId, 'msg-');
-					oElement.textContent = css;
+					css = css.toString();
 					if (SettingsUserStore.removeColors()) {
-						oElement.textContent = oElement.textContent.replace(/(background-)color:[^};]+/g, '');
+						css = css.replace(/(background-)?color:[^};]+;?/g, '');
 					}
+					oElement.textContent = css;
 				} else {
 					oElement.remove();
 				}