Closes: #104

Set cursor.description to None instead of emtpy tuple if no description
is available for rows.

lib/test/regression.py

@@ -1,7 +1,7 @@
 #-*- coding: ISO-8859-1 -*-
 # pysqlite2/test/regression.py: pysqlite regression tests
 #
-# Copyright (C) 2006-2015 Gerhard Häring <gh@ghaering.de>
+# Copyright (C) 2006-2015 Gerhard H�ring <gh@ghaering.de>
 #
 # This file is part of pysqlite.
 #
@@ -332,6 +332,19 @@ def CheckNullCharacter(self):
         self.assertRaises(ValueError, cur.execute, " \0select 2")
         self.assertRaises(ValueError, cur.execute, "select 2\0")
 
+    def CheckNonSelectCursorDescription(self):
+        # https://github.com/ghaering/pysqlite/issues/104
+        con = sqlite.connect(":memory:")
+        cur = con.cursor()
+        cur.execute("create table test as select 1 foo")
+        self.assertEqual(cur.description, None)
+        cur.execute("delete from test")
+        self.assertEqual(cur.description, None)
+        cur.execute("insert into test values (1)")
+        self.assertEqual(cur.description, None)
+        cur.execute("update test set foo=2")
+        self.assertEqual(cur.description, None)
+
 def suite():
     regression_suite = unittest.makeSuite(RegressionTests, "Check")
     return unittest.TestSuite((regression_suite,))

src/cursor.c

@@ -580,11 +580,9 @@ PyObject* _pysqlite_query_execute(pysqlite_Cursor* self, int multiple, PyObject*
         }
 
         if (rc == SQLITE_ROW || rc == SQLITE_DONE) {
-            if (self->description == Py_None) {
-                Py_BEGIN_ALLOW_THREADS
-                numcols = sqlite3_column_count(self->statement->st);
-                Py_END_ALLOW_THREADS
+            numcols = sqlite3_column_count(self->statement->st);
 
+            if (self->description == Py_None && numcols > 0) {
                 Py_DECREF(self->description);
                 self->description = PyTuple_New(numcols);
                 if (!self->description) {