Links rune (#1344)

* shorten links with non-latin properly

* lint: unneeded conversion

backend/app/store/formatter.go

@@ -83,7 +83,8 @@ func (f *CommentFormatter) shortenAutoLinks(commentHTML string, max int) (resHTM
 			if host == "" {
 				return
 			}
-			short := href[:max-3]
+
+			short := string([]rune(href)[:max-3])
 			if len(short) < len(host) {
 				short = host
 			}

backend/app/store/formatter_test.go

@@ -25,6 +25,10 @@ func TestFormatter_FormatText(t *testing.T) {
 			"<p><a href=\"http://127.0.0.1/some-long-link/12345/678901234567890\">http://127.0.0." +
 				"1/some-long-link/12345/6789012...</a></p>\n!converted", "links",
 		},
+		{
+			"something https://amp.dw.com/ru/илон-маск-купил-twitter/a-61590911",
+			"<p>something <a href=\"https://amp.dw.com/ru/илон-маск-купил-twitter/a-61590911\">https://amp.dw.com/ru/илон-маск-купил-twitter...</a></p>\n!converted", "links",
+		},
 		{
 			"something <img src=\"some.png\"/>  _aaa_",
 			"<p>something <img src=\"some.png\" loading=\"lazy\"/>  <em>aaa</em></p>\n!converted",