From ea7c46232f5c20d20b8b812d25ab1c68a30c1434 Mon Sep 17 00:00:00 2001
From: Daniele Varrazzo <daniele.varrazzo@gmail.com>
Date: Fri, 23 Jul 2021 22:59:44 +0200
Subject: [PATCH] Don't register any TypeInfo on oid 0

Someone may conceivably register info of an array only. Let's not
clobber INVALID_OID, I wouldn't know the side effects...
---
 psycopg/psycopg/_typeinfo.py |  3 ++-
 tests/test_typeinfo.py       | 37 ++++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/psycopg/psycopg/_typeinfo.py b/psycopg/psycopg/_typeinfo.py
index fa9103229..b8db91757 100644
--- a/psycopg/psycopg/_typeinfo.py
+++ b/psycopg/psycopg/_typeinfo.py
@@ -259,7 +259,8 @@ class TypesRegistry:
 
     def add(self, info: TypeInfo) -> None:
         self._ensure_own_state()
-        self._by_oid[info.oid] = info
+        if info.oid:
+            self._by_oid[info.oid] = info
         if info.array_oid:
             self._by_oid[info.array_oid] = info
         self._by_name[info.name] = info
diff --git a/tests/test_typeinfo.py b/tests/test_typeinfo.py
index ed792c372..8a209d128 100644
--- a/tests/test_typeinfo.py
+++ b/tests/test_typeinfo.py
@@ -104,3 +104,40 @@ def test_registry_by_builtin_name(conn, name):
     info = psycopg.adapters.types[name]
     assert info.name == "text"
     assert info.oid == 25
+
+
+def test_registry_empty():
+    r = psycopg.types.TypesRegistry()
+    assert r.get("text") is None
+    with pytest.raises(KeyError):
+        r["text"]
+
+
+@pytest.mark.parametrize("oid, aoid", [(1, 2), (1, 0), (0, 2), (0, 0)])
+def test_registry_invalid_oid(oid, aoid):
+    r = psycopg.types.TypesRegistry()
+    ti = psycopg.types.TypeInfo("test", oid, aoid)
+    r.add(ti)
+    assert r["test"] is ti
+    if oid:
+        assert r[oid] is ti
+    if aoid:
+        assert r[aoid] is ti
+    with pytest.raises(KeyError):
+        r[0]
+
+
+def test_registry_copy():
+    r = psycopg.types.TypesRegistry(psycopg.postgres.types)
+    assert r.get("text") is r["text"] is r[25]
+    assert r["text"].oid == 25
+
+
+def test_registry_isolated():
+    orig = psycopg.postgres.types
+    tinfo = orig["text"]
+    r = psycopg.types.TypesRegistry(orig)
+    tdummy = psycopg.types.TypeInfo("dummy", tinfo.oid, tinfo.array_oid)
+    r.add(tdummy)
+    assert r[25] is r["dummy"] is tdummy
+    assert orig[25] is r["text"] is tinfo
-- 
2.47.3