Issue 3306. Better control for a lenght in findmax() function.

Lib/test/test_audioop.py

@@ -161,6 +161,10 @@ class TestAudioop(unittest.TestCase):
             self.assertEqual(audioop.getsample(data[1], 2, i), i)
             self.assertEqual(audioop.getsample(data[2], 4, i), i)
 
+    def test_negavitelen(self):
+        # from issue 3306, previously it segfaulted
+        self.assertRaises(audioop.error,
+            audioop.findmax, ''.join( chr(x) for x in xrange(256)), -2392392)
 
 def test_main():
     run_unittest(TestAudioop)

Modules/audioop.c

@@ -575,7 +575,7 @@ audioop_findmax(PyObject *self, PyObject *args)
         }
         len1 >>= 1;
     
-        if ( len1 < len2 ) {
+        if ( len2 < 0 || len1 < len2 ) {
                 PyErr_SetString(AudioopError, "Input sample should be longer");
                 return 0;
         }