From: Mark Wooding <mdw@distorted.org.uk>
Date: Sun, 24 Nov 2019 16:36:24 +0000 (+0000)
Subject: *.c: Be more careful about `PySequence_Size'.
X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb-python/commitdiff_plain/4281a7ee8646165a39f03bcab908b30dee643dae

*.c: Be more careful about `PySequence_Size'.

This can be implemented by Python, so it can throw exceptions.
Fortunately, Python checks that the result is nonnegative, so we don't
have to worry about that.
---

diff --git a/algorithms.c b/algorithms.c
index d60fe3e..edd73fd 100644
--- a/algorithms.c
+++ b/algorithms.c
@@ -138,9 +138,8 @@ static PyObject *keyszset_pynew(PyTypeObject *ty,
   if (!set) set = PyTuple_New(0);
   else Py_INCREF(set);
   if (!PySequence_Check(set)) TYERR("want a sequence");
-  n = PySequence_Size(set);
-  l = PyList_New(0);
-  if (PyErr_Occurred()) goto end;
+  n = PySequence_Size(set); if (n < 0) goto end;
+  l = PyList_New(0); if (!l) goto end;
   if (dfl < 0) VALERR("key size cannot be negative");
   x = PyInt_FromLong(dfl);
   PyList_Append(l, x);
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;
diff --git a/ec.c b/ec.c
index ef5d855..6280010 100644
--- a/ec.c
+++ b/ec.c
@@ -465,7 +465,7 @@ static int ecptxl_1(ec_curve *c, ec *p, PyObject *x)
     if (!EC_FIND(c, p, xx)) VALERR("not on the curve");
   } else if (PySequence_Check(x)) {
     t = x; x = 0;
-    n = PySequence_Size(t);
+    n = PySequence_Size(t); if (n < 0) goto end;
     if (n != 2 && (n != 3 || !c))
       TYERR("want sequence of two or three items");
     if ((x = PySequence_GetItem(t, 0)) == 0 ||
diff --git a/mp.c b/mp.c
index f2a00b9..ab15d3f 100644
--- a/mp.c
+++ b/mp.c
@@ -1689,7 +1689,8 @@ static PyObject *mcmeth_solve(PyObject *me, PyObject *arg)
     goto end;
   Py_INCREF(q);
   if (!PySequence_Check(q)) TYERR("want a sequence of residues");
-  if (PySequence_Size(q) != n) VALERR("residue count mismatch");
+  i = PySequence_Size(q); if (i < 0) goto end;
+  if (i != n) VALERR("residue count mismatch");
   v = xmalloc(n * sizeof(*v));
   for (i = 0; i < n; i++) {
     if ((x = PySequence_GetItem(q, i)) == 0) goto end;
@@ -1732,8 +1733,7 @@ static PyObject *mpcrt_pynew(PyTypeObject *ty, PyObject *arg, PyObject *kw)
     goto end;
   Py_INCREF(q);
   if (!PySequence_Check(q)) TYERR("want a sequence of moduli");
-  n = PySequence_Size(q);
-  if (PyErr_Occurred()) goto end;
+  n = PySequence_Size(q); if (n < 0) goto end;
   if (!n) VALERR("want at least one modulus");
   v = xmalloc(n * sizeof(*v));
   for (i = 0; i < n; i++) {