Move PyNumber_AsOff_t after whence check

Author: tomasr8

Modules/_io/bufferedio.c

@@ -1383,17 +1383,17 @@ _io__Buffered_seek_impl(buffered *self, PyObject *targetobj, int whence)
         return NULL;
     }
 
-    _PyIO_State *state = find_io_state_by_def(Py_TYPE(self));
-    if (_PyIOBase_check_seekable(state, self->raw, Py_True) == NULL) {
-        return NULL;
-    }
-
     target = PyNumber_AsOff_t(targetobj, PyExc_ValueError);
     if (target == -1 && PyErr_Occurred())
         return NULL;
 
     CHECK_CLOSED(self, "seek of closed file")
 
+    _PyIO_State *state = find_io_state_by_def(Py_TYPE(self));
+    if (_PyIOBase_check_seekable(state, self->raw, Py_True) == NULL) {
+        return NULL;
+    }
+
     /* SEEK_SET and SEEK_CUR are special because we could seek inside the
        buffer. Other whence values must be managed without this optimization.
        Some Operating Systems can provide additional values, like