Don't catch all ValueError

Author: remilapeyre

Lib/ast.py

@@ -520,13 +520,12 @@ def __instancecheck__(cls, inst):
 
 def _new(cls, *args, **kwargs):
     for key in kwargs:
-        try:
-            pos = cls._fields.index(key)
-            if pos < len(args):
-                raise TypeError(f"{cls.__name__} got multiple values for argument {key!r}")
-        except ValueError:
+        if key not in cls._fields:
             # arbitrary keyword arguments are accepted
-            pass
+            continue
+        pos = cls._fields.index(key)
+        if pos < len(args):
+            raise TypeError(f"{cls.__name__} got multiple values for argument {key!r}")
     if cls in _const_types:
         return Constant(*args, **kwargs)
     return Constant.__new__(cls, *args, **kwargs)

Parser/asdl_c.py

@@ -720,17 +720,16 @@ def visitModule(self, mod):
     if (kw) {
         i = 0;  /* needed by PyDict_Next */
         while (PyDict_Next(kw, &i, &key, &value)) {
-            Py_ssize_t p = PySequence_Index(fields, key);
-            PyObject* err = PyErr_Occurred();
-            if (p == -1) {
-                // arbitrary keyword arguments are accepted
-                if (!PyErr_GivenExceptionMatches(err, PyExc_ValueError)) {
+            int contains = PySequence_Contains(fields, key);
+            if (contains == -1) {
+                res = -1;
+                goto cleanup;
+            } else if (contains == 1) {
+                Py_ssize_t p = PySequence_Index(fields, key);
+                if (p == -1) {
                     res = -1;
                     goto cleanup;
                 }
-                PyErr_Clear();
-            }
-            else {
                 if (p < PyTuple_GET_SIZE(args)) {
                     PyErr_Format(PyExc_TypeError,
                         "%.400s got multiple values for argument '%U'",