X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/pyke/blobdiff_plain/c6b05f1ffdddaf4ac857cdbcb00ceff098fca489..b0783435d0481f5034c46c65a0802ca25f646058:/catacomb.c

diff --git a/catacomb.c b/catacomb.c
index daa404a..e24e5ec 100644
--- a/catacomb.c
+++ b/catacomb.c
@@ -76,7 +76,8 @@ PyObject *mexp_common(PyObject *me, PyObject *arg,
     arg = PyTuple_GetItem(arg, 0);
   Py_INCREF(arg);
   if (!PySequence_Check(arg)) TYERR("not a sequence");
-  n = PySequence_Size(arg); if (!n) { z = id(me); goto end; }
+  n = PySequence_Size(arg); if (n < 0) goto end;
+  if (!n) { z = id(me); goto end; }
   x = PySequence_GetItem(arg, 0);
   if (PySequence_Check(x))
     flat = 0;