Fixed adaptation of lists of None

Note: lists of lists of None are not supported yet.

NEWS

@@ -15,6 +15,7 @@ New features:
 What's new in psycopg 2.6.1
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+- Lists consisting of only `None` are escaped correctly (:ticket:`#285`).
 - Fixed deadlock in multithread programs using OpenSSL (:ticket:`#290`).
 - Correctly unlock the connection after error in flush (:ticket:`#294`).
 - Fixed ``MinTimeLoggingCursor.callproc()`` (:ticket:`#309`).

psycopg/adapter_list.c

@@ -39,6 +39,14 @@ list_quote(listObject *self)
     /*  adapt the list by calling adapt() recursively and then wrapping
         everything into "ARRAY[]" */
     PyObject *tmp = NULL, *str = NULL, *joined = NULL, *res = NULL;
+
+    /*  list consisting of only NULL don't work with the ARRAY[] construct
+     *  so we use the {NULL,...} syntax. Note however that list of lists where
+     *  some element is a list of only null still fails: for that we should use
+     *  the '{...}' syntax uniformly but we cannot do it in the current
+     *  infrastructure. TODO in psycopg3 */
+    int all_nulls = 1;
+
     Py_ssize_t i, len;
 
     len = PyList_GET_SIZE(self->wrapped);
@@ -60,6 +68,7 @@ list_quote(listObject *self)
             quoted = microprotocol_getquoted(wrapped,
                                        (connectionObject*)self->connection);
             if (quoted == NULL) goto error;
+            all_nulls = 0;
         }
 
         /* here we don't loose a refcnt: SET_ITEM does not change the
@@ -74,7 +83,12 @@ list_quote(listObject *self)
     joined = PyObject_CallMethod(str, "join", "(O)", tmp);
     if (joined == NULL) goto error;
 
-    res = Bytes_FromFormat("ARRAY[%s]", Bytes_AsString(joined));
+    /* PG doesn't like ARRAY[NULL..] */
+    if (!all_nulls) {
+        res = Bytes_FromFormat("ARRAY[%s]", Bytes_AsString(joined));
+    } else {
+        res = Bytes_FromFormat("'{%s}'", Bytes_AsString(joined));
+    }
 
  error:
     Py_XDECREF(tmp);

tests/test_types_basic.py

@@ -192,6 +192,40 @@ class TypesBasicTests(ConnectingTestCase):
             self.assertRaises(psycopg2.DataError,
                 psycopg2.extensions.STRINGARRAY, b(s), curs)
 
+    def testArrayOfNulls(self):
+        curs = self.conn.cursor()
+        curs.execute("""
+            create table na (
+              texta text[],
+              inta int[],
+              boola boolean[],
+
+              textaa text[][],
+              intaa int[][],
+              boolaa boolean[][]
+            )""")
+
+        curs.execute("insert into na (texta) values (%s)", ([None],))
+        curs.execute("insert into na (texta) values (%s)", (['a', None],))
+        curs.execute("insert into na (texta) values (%s)", ([None, None],))
+        curs.execute("insert into na (inta) values (%s)",  ([None],))
+        curs.execute("insert into na (inta) values (%s)",  ([42, None],))
+        curs.execute("insert into na (inta) values (%s)",  ([None, None],))
+        curs.execute("insert into na (boola) values (%s)", ([None],))
+        curs.execute("insert into na (boola) values (%s)", ([True, None],))
+        curs.execute("insert into na (boola) values (%s)", ([None, None],))
+
+        # TODO: array of array of nulls are not supported yet
+        # curs.execute("insert into na (textaa) values (%s)", ([[None]],))
+        curs.execute("insert into na (textaa) values (%s)", ([['a', None]],))
+        # curs.execute("insert into na (textaa) values (%s)", ([[None, None]],))
+        # curs.execute("insert into na (intaa) values (%s)",  ([[None]],))
+        curs.execute("insert into na (intaa) values (%s)",  ([[42, None]],))
+        # curs.execute("insert into na (intaa) values (%s)",  ([[None, None]],))
+        # curs.execute("insert into na (boolaa) values (%s)", ([[None]],))
+        curs.execute("insert into na (boolaa) values (%s)", ([[True, None]],))
+        # curs.execute("insert into na (boolaa) values (%s)", ([[None, None]],))
+
     @testutils.skip_from_python(3)
     def testTypeRoundtripBuffer(self):
         o1 = buffer("".join(map(chr, range(256))))