Don't linkify when certain unicode formatting characters are present

ts/components/conversation/Linkify.tsx

@@ -6,7 +6,7 @@ import React from 'react';
 import LinkifyIt from 'linkify-it';
 
 import type { RenderTextCallbackType } from '../../types/Util';
-import { isLinkSneaky } from '../../types/LinkPreview';
+import { isLinkSneaky, shouldLinkifyMessage } from '../../types/LinkPreview';
 import { splitByEmoji } from '../../util/emoji';
 import { missingCaseError } from '../../util/missingCaseError';
 
@@ -333,6 +333,10 @@ export class Linkify extends React.Component<Props> {
     | Array<JSX.Element | string | null> {
     const { text, renderNonLink } = this.props;
 
+    if (!shouldLinkifyMessage(text)) {
+      return text;
+    }
+
     // We have to do this, because renderNonLink is not required in our Props object,
     //  but it is always provided via defaultProps.
     if (!renderNonLink) {

ts/test-node/types/LinkPreview_test.ts

@@ -5,6 +5,7 @@ import { assert } from 'chai';
 
 import {
   findLinks,
+  shouldLinkifyMessage,
   shouldPreviewHref,
   isLinkSneaky,
 } from '../../types/LinkPreview';
@@ -44,6 +45,26 @@ describe('Link previews', () => {
     });
   });
 
+  describe('#shouldLinkifyMessage;', () => {
+    it('returns false for strings with directional override characters', () => {
+      assert.isFalse(shouldLinkifyMessage('\u202c'));
+      assert.isFalse(shouldLinkifyMessage('\u202d'));
+      assert.isFalse(shouldLinkifyMessage('\u202e'));
+    });
+
+    it('returns false for strings with unicode drawing characters', () => {
+      assert.isFalse(shouldLinkifyMessage('\u2500'));
+      assert.isFalse(shouldLinkifyMessage('\u2588'));
+      assert.isFalse(shouldLinkifyMessage('\u25FF'));
+    });
+
+    it('returns true other strings', () => {
+      assert.isTrue(shouldLinkifyMessage(null));
+      assert.isTrue(shouldLinkifyMessage(undefined));
+      assert.isTrue(shouldLinkifyMessage('Random other string aqu%C3%AD'));
+    });
+  });
+
   describe('#findLinks', () => {
     it('returns all links if no caretLocation is provided', () => {
       const text =

ts/types/LinkPreview.ts

@@ -38,6 +38,26 @@ export function shouldPreviewHref(href: string): boolean {
   );
 }
 
+const DIRECTIONAL_OVERRIDES = /[\u202c\u202d\u202e]/;
+const UNICODE_DRAWING = /[\u2500-\u25FF]/;
+
+export function shouldLinkifyMessage(
+  message: string | null | undefined
+): boolean {
+  if (!message) {
+    return true;
+  }
+
+  if (DIRECTIONAL_OVERRIDES.test(message)) {
+    return false;
+  }
+  if (UNICODE_DRAWING.test(message)) {
+    return false;
+  }
+
+  return true;
+}
+
 export function isStickerPack(link = ''): boolean {
   return link.startsWith('https://signal.art/addstickers/');
 }
@@ -47,6 +67,10 @@ export function isGroupLink(link = ''): boolean {
 }
 
 export function findLinks(text: string, caretLocation?: number): Array<string> {
+  if (!shouldLinkifyMessage(text)) {
+    return [];
+  }
+
   const haveCaretLocation = isNumber(caretLocation);
   const textLength = text ? text.length : 0;