Do not match nicknames incorrectly as part of a bigger word

Fixes #1776
Fixes #1885

client/js/libs/handlebars/ircmessageparser/findNames.js

@@ -1,17 +1,25 @@
 "use strict";
 
+const nickRegExp = /([\w[\]\\`^{|}-]+)/g;
+
 function findNames(text, users) {
 	const result = [];
-	let index = -1;
 
-	users.forEach((nick) => {
-		index = text.indexOf(nick, ++index);
-		result.push({
-			start: index,
-			end: index + nick.length,
-			nick: nick,
-		});
-	});
+	// Return early if we don't have any nicknames to find
+	if (users.length === 0) {
+		return result;
+	}
+
+	let match;
+	while ((match = nickRegExp.exec(text))) {
+		if (users.indexOf(match[1]) > -1) {
+			result.push({
+				start: match.index,
+				end: match.index + match[1].length,
+				nick: match[1],
+			});
+		}
+	}
 
 	return result;
 }

src/plugins/irc-events/message.js

@@ -4,7 +4,7 @@ const Chan = require("../../models/chan");
 const Msg = require("../../models/msg");
 const LinkPrefetch = require("./link");
 const cleanIrcMessage = require("../../../client/js/libs/handlebars/ircmessageparser/cleanIrcMessage");
-const nickRegExp = /(?:\x03[0-9]{1,2}(?:,[0-9]{1,2})?)?([\w[\]\\`^{|}-]{4,})/g;
+const nickRegExp = /(?:\x03[0-9]{1,2}(?:,[0-9]{1,2})?)?([\w[\]\\`^{|}-]+)/g;
 
 module.exports = function(irc, network) {
 	const client = this;

test/client/js/libs/handlebars/ircmessageparser/findNames.js

@@ -24,6 +24,36 @@ describe("findNames", () => {
 		expect(actual).to.deep.equal(expected);
 	});
 
+	it("should not find nicks as part of a bigger string (issue #1776)", () => {
+		const input = "you're very unlucky, luck";
+		const expected = [
+			{
+				start: 21,
+				end: 25,
+				nick: "luck",
+			},
+		];
+		const nicks = ["luck"];
+		const actual = findNames(input, nicks);
+
+		expect(actual).to.deep.equal(expected);
+	});
+
+	it("should find nicks as short as one character (issue #1885)", () => {
+		const input = "aaa aa abc a";
+		const expected = [
+			{
+				start: 11,
+				end: 12,
+				nick: "a",
+			},
+		];
+		const nicks = ["a"];
+		const actual = findNames(input, nicks);
+
+		expect(actual).to.deep.equal(expected);
+	});
+
 	it("should find same nick multiple times", () => {
 		const input = "xPaw xPaw xPaw";
 		const expected = [