Fix: trying to use emojis with an uppercase letter breaks the message…

… field.

Previoux fix (conversejs#3501) was
wrong and introduced other issues:
* impossible to define an emoji with uppercase letters
* possible to use an emoji 🔤 by using :Abc:, but it won't display

So, the correct fix is just to remove the 'i' modifier for the
shortname_regex, to always have case sensitive emojis.

src/headless/plugins/emoji/api.js

@@ -49,7 +49,7 @@ const emojis = {
             converse.emojis.shortnames = converse.emojis.list.map((m) => m.sn);
             const getShortNames = () =>
                 converse.emojis.shortnames.map((s) => s.replace(/[+]/g, '\\$&')).join('|');
-            converse.emojis.shortnames_regex = new RegExp(getShortNames(), 'gi');
+            converse.emojis.shortnames_regex = new RegExp(getShortNames(), 'g');
             converse.emojis.initialized_promise.resolve();
         }
         return converse.emojis.initialized_promise;

src/headless/plugins/emoji/utils.js

@@ -108,7 +108,7 @@ export function getShortnameReferences (text) {
     }
     const references = [...text.matchAll(converse.emojis.shortnames_regex)].filter(ref => ref[0].length > 0);
     return references.map(ref => {
-        const cp = converse.emojis.by_sn[ref[0].toLowerCase()].cp;
+        const cp = converse.emojis.by_sn[ref[0]].cp;
         return {
             cp,
             'begin': ref.index,
@@ -190,7 +190,7 @@ export function isOnlyEmojis (text) {
     }
     const emojis = words.filter(text => {
         const refs = getCodePointReferences(u.shortnamesToUnicode(text));
-        return refs.length === 1 && (text.toLowerCase() === refs[0]['shortname'] || text === refs[0]['emoji']);
+        return refs.length === 1 && (text === refs[0]['shortname'] || text === refs[0]['emoji']);
     });
     return emojis.length === words.length;
 }