devtools: Handle Qt formatting characters edge-case in update-translations.py

If both numeric format specifiers and "others" are used, assume we're
dealing with a Qt-formatted message. In the case of Qt formatting (see
https://doc.qt.io/qt-5/qstring.html#arg) only numeric formats are
replaced at all. This means "(percentage: %1%)" is valid (which was
introduced in #9461), without needing any kind of escaping that would be
necessary for strprintf.  Without this, this function would wrongly
detect '%)' as a printf format specifier.

contrib/devtools/update-translations.py

@@ -65,6 +65,14 @@ def split_format_specifiers(specifiers):
         else:
             other.append(s)
 
+    # If both numeric format specifiers and "others" are used, assume we're dealing
+    # with a Qt-formatted message. In the case of Qt formatting (see https://doc.qt.io/qt-5/qstring.html#arg)
+    # only numeric formats are replaced at all. This means "(percentage: %1%)" is valid, without needing
+    # any kind of escaping that would be necessary for strprintf. Without this, this function
+    # would wrongly detect '%)' as a printf format specifier.
+    if numeric:
+        other = []
+
     # numeric (Qt) can be present in any order, others (strprintf) must be in specified order
     return set(numeric),other