Preserve hashtag casing in threaded mode

Inspired by f9b23a5d62

app/javascript/flavours/glitch/reducers/compose.js

@@ -39,6 +39,7 @@ import { privacyPreference } from 'flavours/glitch/util/privacy_preference';
 import { me } from 'flavours/glitch/util/initial_state';
 import { overwrite } from 'flavours/glitch/util/js_helpers';
 import { unescapeHTML } from 'flavours/glitch/util/html';
+import { recoverHashtags } from 'flavours/glitch/util/hashtag';
 
 const totalElefriends = 3;
 
@@ -114,8 +115,9 @@ function apiStatusToTextMentions (state, status) {
 }
 
 function apiStatusToTextHashtags (state, status) {
-  return ImmutableOrderedSet([]).union(status.tags.map(
-    ({ name }) => `#${name} `
+  const text = unescapeHTML(status.content);
+  return ImmutableOrderedSet([]).union(recoverHashtags(status.tags, text).map(
+    (name) => `#${name} `
   )).join('');
 }
 

app/javascript/flavours/glitch/util/hashtag.js

@@ -0,0 +1,8 @@
+export function recoverHashtags (recognizedTags, text) {
+  return recognizedTags.map(tag => {
+      const re = new RegExp(`(?:^|[^\/\)\w])#(${tag.name})`, 'i');
+      const matched_hashtag = text.match(re);
+      return matched_hashtag ? matched_hashtag[1] : tag;
+    }
+  );
+}