Recognise v2 info-hashes in clipboard for "Add torrent link" dialog (#15206)

src/gui/downloadfromurldialog.cpp

@@ -49,8 +49,12 @@ namespace
             || str.startsWith("https://", Qt::CaseInsensitive)
             || str.startsWith("ftp://", Qt::CaseInsensitive)
             || str.startsWith("magnet:", Qt::CaseInsensitive)
-            || ((str.size() == 40) && !str.contains(QRegularExpression("[^0-9A-Fa-f]")))
+            || ((str.size() == 40) && !str.contains(QRegularExpression("[^0-9A-Fa-f]"))) // v1 hex-encoded SHA-1 info-hash
-            || ((str.size() == 32) && !str.contains(QRegularExpression("[^2-7A-Za-z]"))));
+#if (LIBTORRENT_VERSION_NUM >= 20000)
+            || ((str.size() == 64) && !str.contains(QRegularExpression("[^0-9A-Fa-f]"))) // v2 hex-encoded SHA-256 info-hash
+#endif
+            || ((str.size() == 32) && !str.contains(QRegularExpression("[^2-7A-Za-z]")))); // v1 Base32 encoded SHA-1 info-hash
+
     }
 }