From fbb4de3dbc39e3874a257b37c5c5104e1f887c86 Mon Sep 17 00:00:00 2001 From: Claire Date: Fri, 21 Apr 2023 18:08:28 +0200 Subject: [PATCH] Fix infinite loop in emoji replacement code (#24615) --- .../mastodon/features/emoji/emoji.js | 60 +++++++++++-------- 1 file changed, 34 insertions(+), 26 deletions(-) diff --git a/app/javascript/mastodon/features/emoji/emoji.js b/app/javascript/mastodon/features/emoji/emoji.js index fe4f6f2869..06800d4329 100644 --- a/app/javascript/mastodon/features/emoji/emoji.js +++ b/app/javascript/mastodon/features/emoji/emoji.js @@ -29,15 +29,15 @@ const emojifyTextNode = (node, customEmojis) => { let i = 0; for (;;) { - let match; + let unicode_emoji; - // Skip to the next potential emoji to replace + // Skip to the next potential emoji to replace (either custom emoji or custom emoji :shortcode: if (customEmojis === null) { - while (i < str.length && !(match = trie.search(str.slice(i)))) { + while (i < str.length && !(unicode_emoji = trie.search(str.slice(i)))) { i += str.codePointAt(i) < 65536 ? 1 : 2; } } else { - while (i < str.length && str[i] !== ':' && !(match = trie.search(str.slice(i)))) { + while (i < str.length && str[i] !== ':' && !(unicode_emoji = trie.search(str.slice(i)))) { i += str.codePointAt(i) < 65536 ? 1 : 2; } } @@ -48,29 +48,37 @@ const emojifyTextNode = (node, customEmojis) => { } let rend, replacement = null; - if (str[i] === ':') { // Potentially the start of a custom emoji shortcode - if (!(rend = str.indexOf(':', i + 1) + 1)) { - continue; // no pair of ':' - } + if (str[i] === ':') { // Potentially the start of a custom emoji :shortcode: + rend = str.indexOf(':', i + 1) + 1; - const shortname = str.slice(i, rend); - // now got a replacee as ':shortname:' - // if you want additional emoji handler, add statements below which set replacement and return true. - if (shortname in customEmojis) { - const filename = autoPlayGif ? customEmojis[shortname].url : customEmojis[shortname].static_url; - replacement = document.createElement('img'); - replacement.setAttribute('draggable', 'false'); - replacement.setAttribute('class', 'emojione custom-emoji'); - replacement.setAttribute('alt', shortname); - replacement.setAttribute('title', shortname); - replacement.setAttribute('src', filename); - replacement.setAttribute('data-original', customEmojis[shortname].url); - replacement.setAttribute('data-static', customEmojis[shortname].static_url); - } else { + // no matching ending ':', skip + if (!rend) { + i++; continue; } - } else { // matched to unicode emoji - rend = i + match.length; + + const shortcode = str.slice(i, rend); + const custom_emoji = customEmojis[shortcode]; + + // not a recognized shortcode, skip + if (!custom_emoji) { + i++; + continue; + } + + // now got a replacee as ':shortcode:' + // if you want additional emoji handler, add statements below which set replacement and return true. + const filename = autoPlayGif ? custom_emoji.url : custom_emoji.static_url; + replacement = document.createElement('img'); + replacement.setAttribute('draggable', 'false'); + replacement.setAttribute('class', 'emojione custom-emoji'); + replacement.setAttribute('alt', shortcode); + replacement.setAttribute('title', shortcode); + replacement.setAttribute('src', filename); + replacement.setAttribute('data-original', custom_emoji.url); + replacement.setAttribute('data-static', custom_emoji.static_url); + } else { // start of an unicode emoji + rend = i + unicode_emoji.length; // If the matched character was followed by VS15 (for selecting text presentation), skip it. if (str.codePointAt(rend - 1) !== VS16 && str.codePointAt(rend) === VS15) { @@ -78,13 +86,13 @@ const emojifyTextNode = (node, customEmojis) => { continue; } - const { filename, shortCode } = unicodeMapping[match]; + const { filename, shortCode } = unicodeMapping[unicode_emoji]; const title = shortCode ? `:${shortCode}:` : ''; replacement = document.createElement('img'); replacement.setAttribute('draggable', 'false'); replacement.setAttribute('class', 'emojione'); - replacement.setAttribute('alt', match); + replacement.setAttribute('alt', unicode_emoji); replacement.setAttribute('title', title); replacement.setAttribute('src', `${assetHost}/emoji/${emojiFilename(filename)}.svg`); }