Usage of g_error in source code causes core dumps

[van-de-bugger]

transmission-daemon-4.0.2-1.fc37.x86_64
transmission-remote-gtk-1.5.1-2.fc37.x86_64

Prerequisites:

1. Transmission daemon is up and running, and have some active torrents (probably, completed).
2. Transmission daemon is running using "transmission" user account.
3. Files in /var/lib/transmission/.config/transmission-daemon/torrents belongs to "transmission" user and not accessible by other users.

Looks like it is standard linux layout.

Steps to reproduce the crash:

1. Run transmission-remote-gtk (I suppose the user does not use "transmission" account).
2. Press Ctrl+O, "Add a Torrent" dialog is shown.
3. Navigate to /var/lib/transmission/.config/transmission-daemon/torrents and select any file, press "Add" button.

Voilà. transmission-remote-gtk crashed. In the terminal:

$ transmission-remote-gtk 
** (transmission-remote-gtk:15132): ERROR **: 01:35:23.063: Failed to open file “/var/lib/transmission/.config/transmission-daemon/torrents/0abc88b24de1a941754bff6f04d8fe8661f4dbe5.torrent”: open() failed: Permission denied
Trace/breakpoint trap (core dumped)

It is not a big problem, but transmission-remote-gtk should not crash if it can't open a torrent file anyway.

[LaserEyess]

Can you get a backtrace for this?

[van-de-bugger]

            Stack trace of thread 15766:
            #0  0x00007f5a69e53757 g_log_structured_array (libglib-2.0.so.0 + 0x5d757)
            #1  0x00007f5a69e53a22 g_log_default_handler (libglib-2.0.so.0 + 0x5da22)
            #2  0x00007f5a69e54e42 g_logv (libglib-2.0.so.0 + 0x5ee42)
            #3  0x00007f5a69e550f3 g_log (libglib-2.0.so.0 + 0x5f0f3)
            #4  0x00005575682f7eed trg_torrent_add_dialog_set_filenames (transmission-remote-gtk + 0x30eed)
            #5  0x00005575682fe20b trg_torrent_add_dialog_constructor (transmission-remote-gtk + 0x3720b)
            #6  0x00007f5a69f5aa14 g_object_new_with_custom_constructor (libgobject-2.0.so.0 + 0x23a14)
            #7  0x00007f5a69f5cdc3 g_object_new_valist (libgobject-2.0.so.0 + 0x25dc3)
            #8  0x00007f5a69f5d41d g_object_new (libgobject-2.0.so.0 + 0x2641d)
            #9  0x00005575682e223f add_cb (transmission-remote-gtk + 0x1b23f)
            #10 0x00007f5a69f4b060 g_closure_invoke (libgobject-2.0.so.0 + 0x14060)
            #11 0x00007f5a69f77f66 signal_emit_unlocked_R.isra.0 (libgobject-2.0.so.0 + 0x40f66)
            #12 0x00007f5a69f684da g_signal_emit_valist (libgobject-2.0.so.0 + 0x314da)
            #13 0x00007f5a69f686f3 g_signal_emit (libgobject-2.0.so.0 + 0x316f3)
            #14 0x00007f5a6a56e5d0 closure_accel_activate (libgtk-3.so.0 + 0x36e5d0)
            #15 0x00007f5a69f4b060 g_closure_invoke (libgobject-2.0.so.0 + 0x14060)
            #16 0x00007f5a69f77f66 signal_emit_unlocked_R.isra.0 (libgobject-2.0.so.0 + 0x40f66)
            #17 0x00007f5a69f67ed6 g_signal_emit_valist (libgobject-2.0.so.0 + 0x30ed6)
            #18 0x00007f5a69f686f3 g_signal_emit (libgobject-2.0.so.0 + 0x316f3)
            #19 0x00007f5a6a2a92cc gtk_accel_group_activate (libgtk-3.so.0 + 0xa92cc)
            #20 0x00007f5a6a2aec9d gtk_accel_groups_activate (libgtk-3.so.0 + 0xaec9d)
            #21 0x00007f5a6a592a66 gtk_window_activate_key (libgtk-3.so.0 + 0x392a66)
            #22 0x00007f5a6a59309c gtk_window_key_press_event.lto_priv.0 (libgtk-3.so.0 + 0x39309c)
            #23 0x00007f5a6a299c57 _gtk_marshal_BOOLEAN__BOXED (libgtk-3.so.0 + 0x99c57)
            #24 0x00007f5a69f4b060 g_closure_invoke (libgobject-2.0.so.0 + 0x14060)
            #25 0x00007f5a69f78095 signal_emit_unlocked_R.isra.0 (libgobject-2.0.so.0 + 0x41095)
            #26 0x00007f5a69f67ed6 g_signal_emit_valist (libgobject-2.0.so.0 + 0x30ed6)
            #27 0x00007f5a69f686f3 g_signal_emit (libgobject-2.0.so.0 + 0x316f3)
            #28 0x00007f5a6a57b074 gtk_widget_event_internal.part.0.lto_priv.0 (libgtk-3.so.0 + 0x37b074)
            #29 0x00007f5a6a40c65f propagate_event.lto_priv.0 (libgtk-3.so.0 + 0x20c65f)
            #30 0x00007f5a6a40d321 gtk_main_do_event (libgtk-3.so.0 + 0x20d321)
            #31 0x00007f5a6992b703 _gdk_event_emit (libgdk-3.so.0 + 0x42703)
            #32 0x00007f5a6997e846 gdk_event_source_dispatch.lto_priv.1 (libgdk-3.so.0 + 0x95846)
            #33 0x00007f5a69e4cc7f g_main_context_dispatch (libglib-2.0.so.0 + 0x56c7f)
            #34 0x00007f5a69ea3118 g_main_context_iterate.constprop.0 (libglib-2.0.so.0 + 0xad118)
            #35 0x00007f5a69e49f00 g_main_context_iteration (libglib-2.0.so.0 + 0x53f00)
            #36 0x00007f5a6a075f7d g_application_run (libgio-2.0.so.0 + 0xdef7d)
            #37 0x00005575682d807e main (transmission-remote-gtk + 0x1107e)
            #38 0x00007f5a69a18510 __libc_start_call_main (libc.so.6 + 0x27510)
            #39 0x00007f5a69a185c9 __libc_start_main@@GLIBC_2.34 (libc.so.6 + 0x275c9)
            #40 0x00005575682d8185 _start (transmission-remote-gtk + 0x11185)
            
            Stack trace of thread 15770:
            #0  0x00007f5a69af021f __poll (libc.so.6 + 0xff21f)
            #1  0x00007f5a69ea308d g_main_context_iterate.constprop.0 (libglib-2.0.so.0 + 0xad08d)
            #2  0x00007f5a69e4c24f g_main_loop_run (libglib-2.0.so.0 + 0x5624f)
            #3  0x00007f5a6a0a7eca gdbus_shared_thread_func.lto_priv.0 (libgio-2.0.so.0 + 0x110eca)
            #4  0x00007f5a69e76982 g_thread_proxy (libglib-2.0.so.0 + 0x80982)
            #5  0x00007f5a69a7c12d start_thread (libc.so.6 + 0x8b12d)
            #6  0x00007f5a69afdbc0 __clone3 (libc.so.6 + 0x10cbc0)
            
            Stack trace of thread 15774:
            #0  0x00007f5a69af592d syscall (libc.so.6 + 0x10492d)
            #1  0x00007f5a69e9e793 g_cond_wait (libglib-2.0.so.0 + 0xa8793)
            #2  0x00007f5a69e1c47b g_async_queue_pop_intern_unlocked (libglib-2.0.so.0 + 0x2647b)
            #3  0x00007f5a69e7b9c1 g_thread_pool_thread_proxy.lto_priv.0 (libglib-2.0.so.0 + 0x859c1)
            #4  0x00007f5a69e76982 g_thread_proxy (libglib-2.0.so.0 + 0x80982)
            #5  0x00007f5a69a7c12d start_thread (libc.so.6 + 0x8b12d)
            #6  0x00007f5a69afdbc0 __clone3 (libc.so.6 + 0x10cbc0)
            
            Stack trace of thread 15776:
            #0  0x00007f5a69af592d syscall (libc.so.6 + 0x10492d)
            #1  0x00007f5a69e9e793 g_cond_wait (libglib-2.0.so.0 + 0xa8793)
            #2  0x00007f5a69e1c47b g_async_queue_pop_intern_unlocked (libglib-2.0.so.0 + 0x2647b)
            #3  0x00007f5a69e7b9c1 g_thread_pool_thread_proxy.lto_priv.0 (libglib-2.0.so.0 + 0x859c1)
            #4  0x00007f5a69e76982 g_thread_proxy (libglib-2.0.so.0 + 0x80982)
            #5  0x00007f5a69a7c12d start_thread (libc.so.6 + 0x8b12d)
            #6  0x00007f5a69afdbc0 __clone3 (libc.so.6 + 0x10cbc0)
            
            Stack trace of thread 15769:
            #0  0x00007f5a69af021f __poll (libc.so.6 + 0xff21f)
            #1  0x00007f5a69ea308d g_main_context_iterate.constprop.0 (libglib-2.0.so.0 + 0xad08d)
            #2  0x00007f5a69e49f00 g_main_context_iteration (libglib-2.0.so.0 + 0x53f00)
            #3  0x00007f5a69e4bb91 glib_worker_main (libglib-2.0.so.0 + 0x55b91)
            #4  0x00007f5a69e76982 g_thread_proxy (libglib-2.0.so.0 + 0x80982)
            #5  0x00007f5a69a7c12d start_thread (libc.so.6 + 0x8b12d)
            #6  0x00007f5a69afdbc0 __clone3 (libc.so.6 + 0x10cbc0)
            
            Stack trace of thread 15888:
            #0  0x00007f5a69af021f __poll (libc.so.6 + 0xff21f)
            #1  0x00007f5a69ea308d g_main_context_iterate.constprop.0 (libglib-2.0.so.0 + 0xad08d)
            #2  0x00007f5a69e49f00 g_main_context_iteration (libglib-2.0.so.0 + 0x53f00)
            #3  0x00007f5a542f038d dconf_gdbus_worker_thread (libdconfsettings.so + 0x738d)
            #4  0x00007f5a69e76982 g_thread_proxy (libglib-2.0.so.0 + 0x80982)
            #5  0x00007f5a69a7c12d start_thread (libc.so.6 + 0x8b12d)
            #6  0x00007f5a69afdbc0 __clone3 (libc.so.6 + 0x10cbc0)
            
            Stack trace of thread 15775:
            #0  0x00007f5a69af592d syscall (libc.so.6 + 0x10492d)
            #1  0x00007f5a69e9e793 g_cond_wait (libglib-2.0.so.0 + 0xa8793)
            #2  0x00007f5a69e1c47b g_async_queue_pop_intern_unlocked (libglib-2.0.so.0 + 0x2647b)
            #3  0x00007f5a69e7b9c1 g_thread_pool_thread_proxy.lto_priv.0 (libglib-2.0.so.0 + 0x859c1)
            #4  0x00007f5a69e76982 g_thread_proxy (libglib-2.0.so.0 + 0x80982)
            #5  0x00007f5a69a7c12d start_thread (libc.so.6 + 0x8b12d)
            #6  0x00007f5a69afdbc0 __clone3 (libc.so.6 + 0x10cbc0)
            
            Stack trace of thread 15782:
            #0  0x00007f5a69af592d syscall (libc.so.6 + 0x10492d)
            #1  0x00007f5a69e9ede0 g_cond_wait_until (libglib-2.0.so.0 + 0xa8de0)
            #2  0x00007f5a69e1c451 g_async_queue_pop_intern_unlocked (libglib-2.0.so.0 + 0x26451)
            #3  0x00007f5a69e7bb0a g_thread_pool_thread_proxy.lto_priv.0 (libglib-2.0.so.0 + 0x85b0a)
            #4  0x00007f5a69e76982 g_thread_proxy (libglib-2.0.so.0 + 0x80982)
            #5  0x00007f5a69a7c12d start_thread (libc.so.6 + 0x8b12d)
            #6  0x00007f5a69afdbc0 __clone3 (libc.so.6 + 0x10cbc0)
            ELF object binary architecture: AMD x86-64

Is this ok?

[LaserEyess]

Ok, I can reproduce this.

sudo touch /tmp/root.torrent
sudo chmod 600 /tmp/root.torrent

Try to open root.torrent with trg. I'll take a look today.

Well...

Error messages are always fatal, resulting in a call to G_BREAKPOINT() to terminate the application. This function will result in a core dump; don’t use it for errors you expect. Using this function indicates a bug in your program, i.e. an assertion failure.

ok then, gotta drop that.

[LaserEyess]

grep -nE 'g_error\(' src/*.c 
src/requests.c:273:            g_error("unable to base64 encode file \"%s\".", target);
src/trg-file-parser.c:192:        g_error("%s", error->message);
src/trg-prefs.c:422:        g_error("Problem creating parent directory (permissions?) for: %s\n", priv->file);
src/trg-prefs.c:448:        g_error("Problem writing configuration file (permissions?) to: %s", priv->file);
src/util.c:190:        g_error("%s", error->message);

I think a proper solution is doing something like #170, but for all of these. The trouble is I am not familiar with libgd (or honestly a lot of deeper GTK stuff) and I would have to experiment a lot. Really this code base needs a lot of refactoring.