v1-0002-plpython-Clean-up-PyModule_AddObject-uses.patch

From a174797efde3b5c0f7ead1fa2a89fde0358ceeed Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Tue, 30 Dec 2025 22:17:57 +0100
Subject: [PATCH v1 2/4] plpython: Clean up PyModule_AddObject() uses

The comments "PyModule_AddObject does not add a refcount to the
object, for some odd reason" seem distracting.  Arguably, this
behavior is expected, not odd.  Also, the additional references
created by the existing code do no seem necessary.  But we should
clean up the reference in the error case, as suggested by the Python
documentation.
---
 src/pl/plpython/plpy_plpymodule.c | 39 ++++++++++++++-----------------
 1 file changed, 18 insertions(+), 21 deletions(-)

diff --git a/src/pl/plpython/plpy_plpymodule.c b/src/pl/plpython/plpy_plpymodule.c
index 66781291519..194739c3db6 100644
--- a/src/pl/plpython/plpy_plpymodule.c
+++ b/src/pl/plpython/plpy_plpymodule.c
@@ -172,18 +172,6 @@ PLy_add_exceptions(PyObject *plpy)
 	PyObject   *excmod;
 	HASHCTL		hash_ctl;
 
-	excmod = PyModule_Create(&PLy_exc_module);
-	if (excmod == NULL)
-		PLy_elog(ERROR, "could not create the spiexceptions module");
-
-	/*
-	 * PyModule_AddObject does not add a refcount to the object, for some odd
-	 * reason; we must do that.
-	 */
-	Py_INCREF(excmod);
-	if (PyModule_AddObject(plpy, "spiexceptions", excmod) < 0)
-		PLy_elog(ERROR, "could not add the spiexceptions module");
-
 	PLy_exc_error = PLy_create_exception("plpy.Error", NULL, NULL,
 										 "Error", plpy);
 	PLy_exc_fatal = PLy_create_exception("plpy.Fatal", NULL, NULL,
@@ -191,12 +179,22 @@ PLy_add_exceptions(PyObject *plpy)
 	PLy_exc_spi_error = PLy_create_exception("plpy.SPIError", NULL, NULL,
 											 "SPIError", plpy);
 
+	excmod = PyModule_Create(&PLy_exc_module);
+	if (excmod == NULL)
+		PLy_elog(ERROR, "could not create the spiexceptions module");
+
 	hash_ctl.keysize = sizeof(int);
 	hash_ctl.entrysize = sizeof(PLyExceptionEntry);
 	PLy_spi_exceptions = hash_create("PL/Python SPI exceptions", 256,
 									 &hash_ctl, HASH_ELEM | HASH_BLOBS);
 
 	PLy_generate_spi_exceptions(excmod, PLy_exc_spi_error);
+
+	if (PyModule_AddObject(plpy, "spiexceptions", excmod) < 0)
+	{
+		Py_XDECREF(excmod);
+		PLy_elog(ERROR, "could not add the spiexceptions module");
+	}
 }
 
 /*
@@ -212,19 +210,18 @@ PLy_create_exception(char *name, PyObject *base, PyObject *dict,
 	if (exc == NULL)
 		PLy_elog(ERROR, NULL);
 
-	/*
-	 * PyModule_AddObject does not add a refcount to the object, for some odd
-	 * reason; we must do that.
-	 */
-	Py_INCREF(exc);
-	PyModule_AddObject(mod, modname, exc);
-
 	/*
 	 * The caller will also store a pointer to the exception object in some
-	 * permanent variable, so add another ref to account for that.  This is
-	 * probably excessively paranoid, but let's be sure.
+	 * permanent variable, so add another ref to account for that.
 	 */
 	Py_INCREF(exc);
+
+	if (PyModule_AddObject(mod, modname, exc) < 0)
+	{
+		Py_XDECREF(exc);
+		PLy_elog(ERROR, "could not add exceptions %s", name);
+	}
+
 	return exc;
 }
 
-- 
2.52.0