If cursor.setinputsizes() is called without any parameters, do not set the flag

indicating that bind variables should be returned since otherwise binding with
named arguments will raise the error "cx_Oracle.ProgrammingError: positional
and named binds cannot be intermixed"
(#199).

Author: anthony-tuininga

src/cxoCursor.c

@@ -1739,7 +1739,10 @@ static PyObject *cxoCursor_setInputSizes(cxoCursor *cursor, PyObject *args,
     else cursor->bindVariables = PyList_New(numPositionalArgs);
     if (!cursor->bindVariables)
         return NULL;
-    cursor->setInputSizes = 1;
+
+    // retain bind variables if any were set
+    if (numKeywordArgs > 0 || numPositionalArgs > 0)
+        cursor->setInputSizes = 1;
 
     // process each input
     if (numKeywordArgs > 0) {

test/Cursor.py

@@ -509,6 +509,12 @@ def testSetInputSizesNegative(self):
                 self.cursor.setinputsizes, val, x = val)
         self.assertRaises(TypeError, self.cursor.setinputsizes, val)
 
+    def testSetInputSizesNoParameters(self):
+        "test setting input sizes without any parameters"
+        self.cursor.setinputsizes()
+        self.cursor.execute("select :val from dual", val = "Test Value")
+        self.assertEqual(self.cursor.fetchall(), [("Test Value",)])
+
     def testSetInputSizesByPosition(self):
         """test setting input sizes with positional args"""
         var = self.cursor.var(cx_Oracle.STRING, 100)