Fixed handling large Oid values

Oid is defined as unsigned 32. On some Python implementations (probably
the ones where maxint = 2 ** 31) this can cause int overflow for large
values (see #961). On my 64 box it doesn't seem the case.

Oid handling was sloppy here and there (messages, casts...): trying to
use uint everywhere, and added a couple of helper macros to treat Oid
consistently.

Close #961.

NEWS

@@ -4,8 +4,10 @@ Current release
 What's new in psycopg 2.8.4
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-Don't swallow keyboard interrupts on connect when a password is specified
+- Don't swallow keyboard interrupts on connect when a password is specified
-in the connection string (:ticket:`#898`).
+  in the connection string (:ticket:`#898`).
+- Fixed int overflow for large values in `~psycopg2.extensions.Column.table_oid`
+  and `~psycopg2.extensions.Column.type_code` (:ticket:`961).
 
 
 What's new in psycopg 2.8.3

psycopg/connection_type.c

@@ -968,7 +968,7 @@ psyco_conn_lobject(connectionObject *self, PyObject *args, PyObject *keywds)
     Dprintf("psyco_conn_lobject: new lobject for connection at %p", self);
     Dprintf("psyco_conn_lobject:     parameters: oid = %u, mode = %s",
             oid, smode);
-    Dprintf("psyco_conn_lobject:     parameters: new_oid = %d, new_file = %s",
+    Dprintf("psyco_conn_lobject:     parameters: new_oid = %u, new_file = %s",
             new_oid, new_file);
 
     if (new_file)

psycopg/cursor_type.c

@@ -1827,7 +1827,7 @@ static struct PyMemberDef cursorObject_members[] = {
         "Number of records ``iter(cur)`` must fetch per network roundtrip."},
     {"description", T_OBJECT, OFFSETOF(description), READONLY,
         "Cursor description as defined in DBAPI-2.0."},
-    {"lastrowid", T_LONG, OFFSETOF(lastoid), READONLY,
+    {"lastrowid", T_OID, OFFSETOF(lastoid), READONLY,
         "The ``oid`` of the last row inserted by the cursor."},
     /* DBAPI-2.0 extensions */
     {"rownumber", T_LONG, OFFSETOF(row), READONLY,

psycopg/lobject_int.c

@@ -176,7 +176,7 @@ lobject_open(lobjectObject *self, connectionObject *conn,
                 self->oid = lo_creat(self->conn->pgconn, INV_READ | INV_WRITE);
         }
 
-        Dprintf("lobject_open: large object created with oid = %d",
+        Dprintf("lobject_open: large object created with oid = %u",
                 self->oid);
 
         if (self->oid == InvalidOid) {

psycopg/lobject_type.c

@@ -327,7 +327,7 @@ static struct PyMethodDef lobjectObject_methods[] = {
 /* object member list */
 
 static struct PyMemberDef lobjectObject_members[] = {
-    {"oid", T_UINT, offsetof(lobjectObject, oid), READONLY,
+    {"oid", T_OID, offsetof(lobjectObject, oid), READONLY,
         "The backend OID associated to this lobject."},
     {"mode", T_STRING, offsetof(lobjectObject, smode), READONLY,
         "Open mode."},
@@ -368,7 +368,7 @@ lobject_setup(lobjectObject *self, connectionObject *conn,
 
    Dprintf("lobject_setup: good lobject object at %p, refcnt = "
            FORMAT_CODE_PY_SSIZE_T, self, Py_REFCNT(self));
-   Dprintf("lobject_setup:    oid = %d, fd = %d", self->oid, self->fd);
+   Dprintf("lobject_setup:    oid = %u, fd = %d", self->oid, self->fd);
    return 0;
 }
 

psycopg/pqpath.c

@@ -995,9 +995,9 @@ _get_cast(cursorObject *curs, PGresult *pgres, int i)
     PyObject *rv = NULL;
 
     Oid ftype = PQftype(pgres, i);
-    if (!(type = PyInt_FromLong(ftype))) { goto exit; }
+    if (!(type = PyLong_FromOid(ftype))) { goto exit; }
 
-    Dprintf("_pq_fetch_tuples: looking for cast %d:", ftype);
+    Dprintf("_pq_fetch_tuples: looking for cast %u:", ftype);
     if (!(cast = curs_get_cast(curs, type))) { goto exit; }
 
     /* else if we got binary tuples and if we got a field that
@@ -1006,11 +1006,11 @@ _get_cast(cursorObject *curs, PGresult *pgres, int i)
     */
     if (cast == psyco_default_binary_cast && PQbinaryTuples(pgres)) {
         Dprintf("_pq_fetch_tuples: Binary cursor and "
-                "binary field: %i using default cast", ftype);
+                "binary field: %u using default cast", ftype);
         cast = psyco_default_cast;
     }
 
-    Dprintf("_pq_fetch_tuples: using cast at %p for type %d", cast, ftype);
+    Dprintf("_pq_fetch_tuples: using cast at %p for type %u", cast, ftype);
 
     /* success */
     Py_INCREF(cast);
@@ -1041,7 +1041,7 @@ _make_column(connectionObject *conn, PGresult *pgres, int i)
     /* fill the type and name fields */
     {
         PyObject *tmp;
-        if (!(tmp = PyInt_FromLong(ftype))) {
+        if (!(tmp = PyLong_FromOid(ftype))) {
             goto exit;
         }
         column->type_code = tmp;
@@ -1099,7 +1099,7 @@ _make_column(connectionObject *conn, PGresult *pgres, int i)
     /* table_oid, table_column */
     if (ftable != InvalidOid) {
         PyObject *tmp;
-        if (!(tmp = PyInt_FromLong((long)ftable))) { goto exit; }
+        if (!(tmp = PyLong_FromOid(ftable))) { goto exit; }
         column->table_oid = tmp;
     }
 

psycopg/python.h

@@ -91,6 +91,11 @@ typedef unsigned long Py_uhash_t;
 
 #define INIT_MODULE(m) init ## m
 
+/* fix #961, but don't change all types to longs. Sure someone will complain. */
+#define PyLong_FromOid(x) (((x) & 0x80000000) ? \
+    PyLong_FromUnsignedLong((unsigned long)(x)) : \
+    PyInt_FromLong((x)))
+
 #endif  /* PY_2 */
 
 #if PY_3
@@ -133,6 +138,11 @@ typedef unsigned long Py_uhash_t;
 
 #define INIT_MODULE(m) PyInit_ ## m
 
+#define PyLong_FromOid(x) (PyLong_FromUnsignedLong((unsigned long)(x)))
+
 #endif  /* PY_3 */
 
+/* expose Oid attributes in Python C objects */
+#define T_OID T_UINT
+
 #endif /* !defined(PSYCOPG_PYTHON_H) */