Bugfix: MIME parser RegExp didn't escape boundary which caused issues

dev/Mime/Parser.js

@@ -175,7 +175,7 @@ export function ParseMime(text)
 			let boundary = headers['content-type']?.params.boundary;
 			if (boundary) {
 				part.boundary = boundary;
-				let regex = new RegExp('(?:^|\r?\n)--' + boundary + '(?:--)?(?:\r?\n|$)', 'g'),
+				let regex = new RegExp('(?:^|\r?\n)--' + RegExp.escape(boundary) + '(?:--)?(?:\r?\n|$)', 'g'),
 					body = mimePart.slice(head.length),
 					bodies = body.split(regex),
 					pos = part.bodyStart;

dev/prototype.js

@@ -44,6 +44,13 @@
 		return template.content.firstChild;
 	};
 
+	/**
+	 * https://github.com/tc39/proposal-regex-escaping
+	 */
+	if (!RegExp.escape){
+		RegExp.escape = s => String(s).replace(/[\\^$*+?.()|[\]{}]/g, '\\$&');
+	}
+
 	/**
 	 * Every time the function is executed,
 	 * it will delay the execution with the given amount of milliseconds.