In replace_shortnames(), avoid repeated emojis.

html.c

@@ -72,6 +72,9 @@ xs_str *replace_shortnames(xs_str *s, const xs_list *tag, int ems, const char *p
         const xs_dict *v;
         int c = 0;
 
+        xs_set rep_emoji;
+        xs_set_init(&rep_emoji);
+
         while (xs_list_next(tag_list, &v, &c)) {
             const char *t = xs_dict_get(v, "type");
 
@@ -79,6 +82,10 @@ xs_str *replace_shortnames(xs_str *s, const xs_list *tag, int ems, const char *p
                 const char *n = xs_dict_get(v, "name");
                 const xs_dict *i = xs_dict_get(v, "icon");
 
+                /* avoid repeated emojis (Misskey seems to return this) */
+                if (xs_set_add(&rep_emoji, n) == 0)
+                    continue;
+
                 if (xs_is_string(n) && xs_is_dict(i)) {
                     const char *u = xs_dict_get(i, "url");
                     const char *mt = xs_dict_get(i, "mediaType");
@@ -104,6 +111,8 @@ xs_str *replace_shortnames(xs_str *s, const xs_list *tag, int ems, const char *p
                 }
             }
         }
+
+        xs_set_free(&rep_emoji);
     }
 
     return s;