fix: tighten emoji lookup contracts

tests/dict_test.c

@@ -89,3 +89,28 @@ dictionary_misses_clear_result(struct ct *t)
 	hmapfree(lang->dict);
 	lang->dict = saved;
 }
+
+void
+dictionary_emoji_identity(struct ct *t)
+{
+	Dictreq req;
+	Dictres res;
+	Hmap *saved;
+	Lang *lang;
+	Str key;
+
+	lang = getlang(LangEMOJI);
+	saved = lang->dict;
+	lang->dict = hmapalloc(2);
+	key = mkstr("é");
+	hmapset(&lang->dict, &key, "é", strlen("é"));
+	memset(&req, 0, sizeof req);
+	req.key = key;
+	req.pre = key;
+	req.lang = LangEMOJI;
+	dictlookup(&req, &res);
+	if(CT_EQ_INT(t, 1, res.nkouho))
+		checkstr(t, "emoji identity candidate", "é", &res.kouho[0]);
+	hmapfree(lang->dict);
+	lang->dict = saved;
+}