From: Michael Tremer <michael.tremer@ipfire.org>
Date: Tue, 21 Sep 2021 16:14:25 +0000 (+0000)
Subject: python: Prevent early deallocation of logging callback
X-Git-Tag: 0.9.28~946
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a02be46b92eb66a54f9a692a5571a523e859c7a2;p=pakfire.git

python: Prevent early deallocation of logging callback

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/_pakfire/pakfire.c b/src/_pakfire/pakfire.c
index f6784db9e..9c4401d3e 100644
--- a/src/_pakfire/pakfire.c
+++ b/src/_pakfire/pakfire.c
@@ -108,6 +108,7 @@ static int Pakfire_init(PakfireObject* self, PyObject* args, PyObject* kwds) {
 		"enable_ccache", "enable_snapshot", NULL };
 	const char* path = NULL;
 	const char* arch = NULL;
+	PyObject* logger = NULL;
 	const char* conf = NULL;
 	int offline = 0;
 	int build = 0;
@@ -115,12 +116,12 @@ static int Pakfire_init(PakfireObject* self, PyObject* args, PyObject* kwds) {
 	int enable_snapshot = 1;
 
 	if (!PyArg_ParseTupleAndKeywords(args, kwds, "|zzOpzppp", kwlist,
-			&path, &arch, &self->logger, &offline, &conf, &build,
+			&path, &arch, &logger, &offline, &conf, &build,
 			&enable_ccache, &enable_snapshot))
 		return -1;
 
 	// Check if logger is callable
-	if (self->logger && !PyCallable_Check(self->logger)) {
+	if (logger && !PyCallable_Check(logger)) {
 		PyErr_SetString(PyExc_TypeError, "logger must be callable\n");
 		return -1;
 	}
@@ -144,7 +145,7 @@ static int Pakfire_init(PakfireObject* self, PyObject* args, PyObject* kwds) {
 
 	// Create a new Pakfire instance
 	int r = pakfire_create(&self->pakfire, path, arch, conf, flags,
-			(self->logger) ? Pakfire_logging_callback : NULL, self->logger);
+			(logger) ? Pakfire_logging_callback : NULL, logger);
 	if (r) {
 		switch (errno) {
 			// Invalid architecture or path
@@ -160,7 +161,11 @@ static int Pakfire_init(PakfireObject* self, PyObject* args, PyObject* kwds) {
 		return -1;
     }
 
-	Py_XINCREF(self->logger);
+	// Store a reference to the logger
+	if (logger) {
+		self->logger = logger;
+		Py_INCREF(self->logger);
+	}
 
 	return 0;
 }
@@ -169,8 +174,18 @@ static void Pakfire_dealloc(PakfireObject* self) {
 	if (self->pakfire)
 		pakfire_unref(self->pakfire);
 
+#if 0
+	/*
+		It might happen, that the Pakfire python object is deallocated but the
+		actual struct pakfire object isn't yet. However, it might still happen
+		that the logging function is called which will try to call the logging
+		callback which has already been deallocated.
+
+		TODO This has to move into struct pakfire or something similar.
+	*/
 	if (self->logger)
 		Py_DECREF(self->logger);
+#endif
 
 	Py_TYPE(self)->tp_free((PyObject *)self);
 }