Fix infinite loop in emoji replacement code (#24615)

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Claire 2023-04-21 18:08:28 +02:00 committed by GitHub
parent b0eba1a060
commit fbb4de3dbc
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1 changed files with 34 additions and 26 deletions

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@ -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;
// no matching ending ':', skip
if (!rend) {
i++;
continue;
}
const shortname = str.slice(i, rend);
// now got a replacee as ':shortname:'
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.
if (shortname in customEmojis) {
const filename = autoPlayGif ? customEmojis[shortname].url : customEmojis[shortname].static_url;
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', shortname);
replacement.setAttribute('title', shortname);
replacement.setAttribute('alt', shortcode);
replacement.setAttribute('title', shortcode);
replacement.setAttribute('src', filename);
replacement.setAttribute('data-original', customEmojis[shortname].url);
replacement.setAttribute('data-static', customEmojis[shortname].static_url);
} else {
continue;
}
} else { // matched to unicode emoji
rend = i + match.length;
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`);
}