Workaround a StandardOutput formatting bug

mathics/format/form/outputform.py

@@ -265,12 +265,12 @@ def render_output_form(expr: BaseElement, evaluation: Evaluation, **kwargs):
             callback = _default_render_output_form
     try:
         result = callback(format_expr, evaluation, **kwargs)
-        return result
-    except _WrongFormattedExpression:
+    except Exception:
         # If the key is not present, or the execution fails for any reason, use
         # the default
-        pass
-    return _default_render_output_form(format_expr, evaluation, **kwargs)
+        return _default_render_output_form(format_expr, evaluation, **kwargs)
+    else:
+        return result
 
 
 @register_outputform("System`Format")

test/builtin/string/test_operations.py

@@ -43,6 +43,13 @@
             "StringTake[]",
             "StringTake argument checking",
         ),
+        (
+            'xx = "a string"; StringTake[xx[0]]',
+            ("StringTake called with 1 argument; 2 arguments are expected.",),
+            "StringTake[a string[0]]",
+            "StringTake bug in formatting",
+        ),
+        ("Clear[xx]", None, None, None),
     ],
 )
 def test_string_take(str_expr, msgs, str_expected, fail_msg):