Re: #3457 (#3614)

* Update parser.ts

* Update user.ts

* Update search.ts

* Update parser.ts

* Update parser.ts

* Update parser.ts

* Update parser.ts

* Update parser.ts

* Update parser.ts

* Update mfm.ts

* Update parser.ts

* Merge branch 'develop' into 3440-mk2

* Fix typo

* Update parser.ts

* Update mfm.ts

* Update mfm.ts

src/mfm/parser.ts

@@ -275,7 +275,7 @@ const mfm = P.createLanguage({
 	mention: r =>
 		P((input, i) => {
 			const text = input.substr(i);
-			const match = text.match(/^@[a-z0-9_]+(?:@[a-z0-9\.\-]+[a-z0-9])?/i);
+			const match = text.match(/^@\w([\w-]*\w)?(?:@[\w\.\-]+\w)?/);
 			if (!match) return P.makeFailure(i, 'not a mention');
 			if (input[i - 1] != null && input[i - 1].match(/[a-z0-9]/i)) return P.makeFailure(i, 'not a mention');
 			return P.makeSuccess(i + match[0].length, match[0]);

src/models/user.ts

@@ -155,7 +155,7 @@ export const isRemoteUser = (user: any): user is IRemoteUser =>
 
 //#region Validators
 export function validateUsername(username: string, remote?: boolean): boolean {
-	return typeof username == 'string' && (remote ? /^\w+([\w\.-]+\w+)?$/ : /^[a-zA-Z0-9_]{1,20}$/).test(username);
+	return typeof username == 'string' && (remote ? /^\w([\w-]*\w)?$/ : /^\w{1,20}$/).test(username);
 }
 
 export function validatePassword(password: string): boolean {

src/server/api/endpoints/users/search.ts

@@ -53,7 +53,7 @@ export const meta = {
 };
 
 export default define(meta, (ps, me) => new Promise(async (res, rej) => {
-	const isUsername = validateUsername(ps.query.replace('@', ''), true);
+	const isUsername = validateUsername(ps.query.replace('@', ''), !ps.localOnly);
 
 	let users: IUser[] = [];