From f475cc39efea62441042ba6ac0b8e6e08c24134c Mon Sep 17 00:00:00 2001
From: Pavel Djundik <github@xpaw.me>
Date: Thu, 8 Mar 2018 19:43:39 +0200
Subject: [PATCH] Normalize unicode URLs in link prefetcher

Fixes #1644
---
 src/plugins/irc-events/link.js | 17 +++++---------
 test/plugins/link.js           | 43 ++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 11 deletions(-)

diff --git a/src/plugins/irc-events/link.js b/src/plugins/irc-events/link.js
index 46c66adb..8d4ca196 100644
--- a/src/plugins/irc-events/link.js
+++ b/src/plugins/irc-events/link.js
@@ -3,6 +3,7 @@
 const cheerio = require("cheerio");
 const request = require("request");
 const url = require("url");
+const URI = require("urijs");
 const mime = require("mime-types");
 const Helper = require("../../helper");
 const cleanIrcMessage = require("../../../client/js/libs/handlebars/ircmessageparser/cleanIrcMessage");
@@ -40,7 +41,7 @@ module.exports = function(client, chan, msg) {
 	}
 
 	msg.previews = Array.from(new Set( // Remove duplicate links
-		links.map((link) => escapeHeader(link.link))
+		links.map((link) => normalizeURL(link.link))
 	)).map((link) => ({
 		type: "loading",
 		head: "",
@@ -101,7 +102,7 @@ function parseHtml(preview, res, client) {
 
 				// Verify that thumbnail pic exists and is under allowed size
 				if (preview.thumb.length) {
-					fetch(escapeHeader(preview.thumb), {language: client.language}, (resThumb) => {
+					fetch(normalizeURL(preview.thumb), {language: client.language}, (resThumb) => {
 						if (resThumb === null
 						|| !(/^image\/.+/.test(resThumb.type))
 						|| resThumb.size > (Helper.config.prefetchMaxImageSize * 1024)) {
@@ -140,7 +141,7 @@ function parseHtmlMedia($, preview, res, client) {
 
 					foundMedia = true;
 
-					fetch(escapeHeader(mediaUrl), {language: client.language}, (resMedia) => {
+					fetch(normalizeURL(mediaUrl), {language: client.language}, (resMedia) => {
 						if (resMedia === null || !mediaTypeRegex.test(resMedia.type)) {
 							return reject();
 						}
@@ -356,12 +357,6 @@ function fetch(uri, {language}, cb) {
 		});
 }
 
-// https://github.com/request/request/issues/2120
-// https://github.com/nodejs/node/issues/1693
-// https://github.com/alexeyten/descript/commit/50ee540b30188324198176e445330294922665fc
-function escapeHeader(header) {
-	return header
-		.replace(/([\uD800-\uDBFF][\uDC00-\uDFFF])+/g, encodeURI)
-		.replace(/[\uD800-\uDFFF]/g, "")
-		.replace(/[\u0000-\u001F\u007F-\uFFFF]+/g, encodeURI);
+function normalizeURL(header) {
+	return URI(header).normalize().toString();
 }
diff --git a/test/plugins/link.js b/test/plugins/link.js
index 1721477c..cc06d672 100644
--- a/test/plugins/link.js
+++ b/test/plugins/link.js
@@ -283,4 +283,47 @@ describe("Link plugin", function() {
 
 		link(this.irc, this.network.channels[0], message);
 	});
+
+	it("should work on non-ASCII urls", function(done) {
+		const message = this.irc.createMessage({
+			text:
+			"http://localhost:9002/unicode/ıoı-test " +
+			"http://localhost:9002/unicode/русский-текст-test " +
+			"http://localhost:9002/unicode/🙈-emoji-test " +
+			"http://localhost:9002/unicodeq/?q=ıoı-test " +
+			"http://localhost:9002/unicodeq/?q=русский-текст-test " +
+			"http://localhost:9002/unicodeq/?q=🙈-emoji-test",
+		});
+
+		link(this.irc, this.network.channels[0], message);
+
+		app.get("/unicode/:q", function(req, res) {
+			res.send(`<title>${req.params.q}</title>`);
+		});
+
+		app.get("/unicodeq/", function(req, res) {
+			res.send(`<title>${req.query.q}</title>`);
+		});
+
+		const previews = [];
+
+		this.irc.on("msg:preview", function(data) {
+			previews.push(data.preview.link);
+
+			if (data.preview.link.indexOf("%C4%B1o%C4%B1-test") > 0) {
+				expect(data.preview.head).to.equal("ıoı-test");
+			} else if (data.preview.link.indexOf("%D1%80%D1%83%D1%81%D1%81%D0%BA%D0%B8%D0%B9-%D1%82%D0%B5%D0%BA%D1%81%D1%82-test") > 0) {
+				expect(data.preview.head).to.equal("русский-текст-test");
+			} else if (data.preview.link.indexOf("%F0%9F%99%88-emoji-test") > 0) {
+				expect(data.preview.head).to.equal("🙈-emoji-test");
+			} else {
+				expect("This should never happen").to.equal(data.preview.link);
+			}
+
+			if (previews.length === 5) {
+				expect(message.previews.map((preview) => preview.link)).to.deep.equal(previews);
+				done();
+			}
+		});
+	});
 });