Backport patch to fix leaking log handlers in Sack

0003-Fix-leaking-log-handlers-in-Sack.patch

@@ -0,0 +1,92 @@
+From 4503d8c017b1c625d65b22279a7e136ec962984c Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Luk=C3=A1=C5=A1=20Hr=C3=A1zk=C3=BD?= <lhrazky@redhat.com>
+Date: Mon, 7 Oct 2019 16:33:48 +0200
+Subject: [PATCH] Fix leaking log handlers in Sack (RhBug:1758737)
+
+Stores the log handler ids in the sack and uses g_log_remove_handler()
+in the sack destructor to remove the handlers.
+
+The mechanism is a bit complex and is explained in a code comment.
+
+https://bugzilla.redhat.com/show_bug.cgi?id=1758737
+---
+ python/hawkey/sack-py.cpp | 35 ++++++++++++++++++++++++++++-------
+ 1 file changed, 28 insertions(+), 7 deletions(-)
+
+diff --git a/python/hawkey/sack-py.cpp b/python/hawkey/sack-py.cpp
+index 5e39dda69..5a1c10d1a 100644
+--- a/python/hawkey/sack-py.cpp
++++ b/python/hawkey/sack-py.cpp
+@@ -52,6 +52,22 @@ typedef struct {
+     PyObject *custom_package_class;
+     PyObject *custom_package_val;
+     PyObject * ModulePackageContainerPy;
++
++    // g_log handler IDs
++    // Multiple sacks can be created during a run of an application and each
++    // sack opens a log file and registers two g_log handlers. To avoid dangling
++    // handlers with invalid FILE pointers (we close them when destroying the
++    // sack), we need to keep track of the handlers so that we can also remove
++    // them.
++    //
++    // g_log is clever about adding log handlers. It does store all handlers
++    // registered for a given domain, but only the one that was registered last
++    // is used. If you remove the last registered one, the next in line will be
++    // used. That means stacking sacks is ok, the handler from the last
++    // undeleted sack will be the one that is used.
++    guint default_log_handler_id;
++    guint libdnf_log_handler_id;
++
+     FILE *log_out;
+ } _SackObject;
+ 
+@@ -131,8 +147,13 @@ sack_dealloc(_SackObject *o)
+         }
+         g_object_unref(o->sack);
+     }
+-    if (o->log_out)
++
++    if (o->log_out) {
++        g_log_remove_handler(nullptr, o->default_log_handler_id);
++        g_log_remove_handler("libdnf", o->libdnf_log_handler_id);
+         fclose(o->log_out);
++    }
++
+     Py_TYPE(o)->tp_free(o);
+ }
+ 
+@@ -194,11 +215,11 @@ log_handler_noop(const gchar *, GLogLevelFlags, const gchar *, gpointer)
+ }
+ 
+ static gboolean
+-set_logfile(const gchar *path, FILE ** log_out, bool debug)
++sack_set_logfile(_SackObject *self, const gchar *path, bool debug)
+ {
+-    *log_out = fopen(path, "a");
++    self->log_out = fopen(path, "a");
+ 
+-    if (!(*log_out))
++    if (!self->log_out)
+         return FALSE;
+ 
+     // The default log handler prints messages that weren't handled by any
+@@ -213,8 +234,8 @@ set_logfile(const gchar *path, FILE ** log_out, bool debug)
+         G_LOG_LEVEL_ERROR);
+ 
+     // set the handler for the default domain as well as "libdnf"
+-    g_log_set_handler(nullptr, log_mask, log_handler, *log_out);
+-    g_log_set_handler("libdnf", log_mask, log_handler, *log_out);
++    self->default_log_handler_id = g_log_set_handler(nullptr, log_mask, log_handler, self->log_out);
++    self->libdnf_log_handler_id = g_log_set_handler("libdnf", log_mask, log_handler, self->log_out);
+ 
+     g_info("=== Started libdnf-%d.%d.%d ===", LIBDNF_MAJOR_VERSION,
+             LIBDNF_MINOR_VERSION, LIBDNF_MICRO_VERSION);
+@@ -273,7 +294,7 @@ sack_init(_SackObject *self, PyObject *args, PyObject *kwds)
+         PycompString logfile(logfile_py);
+         if (!logfile.getCString())
+             return -1;
+-        if (!set_logfile(logfile.getCString(), &self->log_out, debug)) {
++        if (!sack_set_logfile(self, logfile.getCString(), debug)) {
+             PyErr_Format(PyExc_IOError, "Failed to open log file: %s", logfile.getCString());
+             return -1;
+         }

libdnf.spec

@@ -44,13 +44,14 @@
 
 Name:           libdnf
 Version:        0.35.5
-Release:        3%{?dist}
+Release:        4%{?dist}
 Summary:        Library providing simplified C and Python API to libsolv
 License:        LGPLv2+
 URL:            https://github.com/rpm-software-management/libdnf
 Source0:        %{url}/archive/%{version}/%{name}-%{version}.tar.gz
 Patch0001:      0001-Revert-9309e92332241ff1113433057c969cebf127734e.patch
 Patch0002:      0001-Use-POOL_FLAG_WHATPROVIDESWITHDISABLED.patch
+Patch0003:      0003-Fix-leaking-log-handlers-in-Sack.patch
 
 BuildRequires:  cmake
 BuildRequires:  gcc
@@ -284,6 +285,9 @@ popd
 %endif
 
 %changelog
+* Tue Oct 22 2019 Ales Matej <amatej@redhat.com> - 0.35.5-4
+- Fix leaking log handlers in Sack that can cause a crash (RhBug:1758737)
+
 * Mon Oct 14 2019 Jaroslav Mracek <jmracek@redhat.com> - 0.35.5-3
 - Add POOL_FLAG_WHATPROVIDESWITHDISABLED flag into pool.
 - Resolves: 1737469
@@ -312,7 +316,7 @@ popd
 * Wed Sep 11 2019 Jaroslav Mracek <jmracek@redhat.com> - 0.35.3-4
 - Backport patch to fix reinstalling packages with a different buildtime - part II
 
-* Thu Sep 10 2019 Jaroslav Mracek <jmracek@redhat.com> - 0.35.3-3
+* Tue Sep 10 2019 Jaroslav Mracek <jmracek@redhat.com> - 0.35.3-3
 - Backport patch to fix reinstalling packages with a different buildtime
 
 * Thu Aug 15 2019 Miro Hrončok <mhroncok@redhat.com> - 0.35.3-2