Created attachment 1058594 [details]
experimental fix

Description of problem:
gnome-terminal in wayland segfaults, no idea how to reproduce

Patch checks for NULL, I didn't actually try to figure out the root cause :)

Version-Release number of selected component (if applicable):
3.16.6

How reproducible:


Steps to Reproduce:
1.
2.
3.

Actual results:
(gdb) bt
#0  0x00007f816976a640 in _gtk_bin_set_child (bin=0x0, widget=widget@entry=0x0) at gtkbin.c:338
#1  0x00007f816989b51e in gtk_notebook_drag_end (widget=0x24feca0, context=<optimized out>) at gtknotebook.c:3734
#2  0x00007f8167f6a337 in g_cclosure_marshal_VOID__OBJECTv () at /lib64/libgobject-2.0.so.0
#3  0x00007f8167f67214 in _g_closure_invoke_va () at /lib64/libgobject-2.0.so.0
#4  0x00007f8167f835cd in g_signal_emit_valist () at /lib64/libgobject-2.0.so.0
#5  0x00007f8167f84155 in g_signal_emit_by_name () at /lib64/libgobject-2.0.so.0
#6  0x00007f81699c95b5 in gtk_drag_source_info_destroy (info=0x3cefaf0) at gtkdnd.c:4056
#7  0x00007f81699c95cc in gtk_drag_anim_destroy (anim=0x23fe560) at gtkdnd.c:3959
#8  0x00007f81693ba7d8 in gdk_threads_dispatch_free (data=0x36518c0) at gdk.c:732
#9  0x00007f8167c50e88 in g_source_callback_unref (cb_data=0x376a760) at gmain.c:1532
#10 0x00007f8167c544c4 in g_source_destroy_internal (source=0x3db1c10, context=0x22f30c0, have_lock=1) at gmain.c:1178
#11 0x00007f8167c568bb in g_main_context_dispatch (context=0x22f30c0) at gmain.c:3145
#12 0x00007f8167c568bb in g_main_context_dispatch (context=context@entry=0x22f30c0) at gmain.c:3737
#13 0x00007f8167c56bd0 in g_main_context_iterate (context=context@entry=0x22f30c0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3808
#14 0x00007f8167c56c7c in g_main_context_iteration (context=0x22f30c0, context@entry=0x0, may_block=may_block@entry=1)
    at gmain.c:3869
#15 0x00007f816826b42c in g_application_run (application=application@entry=0x22ff4d0, argc=argc@entry=0, argv=argv@entry=0x0) at gapplication.c:2311
#16 0x0000000000412193 in main (argc=1, argv=0x7ffe2ce96508) at server.c:173
(gdb) frame 0
#0  _gtk_bin_set_child (bin=0x0, widget=widget@entry=0x0) at gtkbin.c:338
338	  bin->priv->child = widget;
(gdb) frame 1
#1  0x00007f816989b51e in gtk_notebook_drag_end (widget=0x24feca0, context=<optimized out>) at gtknotebook.c:3734
3734	  _gtk_bin_set_child (GTK_BIN (priv->dnd_window), NULL);
(gdb) p priv
$1 = (GtkNotebookPrivate *) 0x24feae0
(gdb) p *priv
$2 = {operation = DRAG_OPERATION_NONE, cur_page = 0x2c718a0, detached_tab = 0x2c718a0, prelight_tab = 0x0, 
  source_targets = 0x296bf00, action_widget = {0x0, 0x0}, dnd_window = 0x0, menu = 0x0, drag_window = 0x352a930, 
Python Exception <class 'TypeError'> iter() returned non-iterator of type '_iterator': 
Python Exception <class 'TypeError'> iter() returned non-iterator of type '_iterator': 
Python Exception <class 'TypeError'> iter() returned non-iterator of type '_iterator': 
  event_window = 0x2c9da80, children = 0x2caab00, first_tab = 0x2caab00, focus_tab = 0x2caab00, drag_begin_x = 609, 
  drag_begin_y = 99, drag_offset_x = 121, drag_offset_y = 8, drag_window_x = 286, drag_window_y = 91, mouse_x = 342, 
  mouse_y = 602, pressed_button = -1, group = 1593, dnd_timer = 0, Python Exception <class 'TypeError'> iter() returned non-iterator of type '_iterator': 
switch_tab_timer = 0, switch_tab = 0x0, timer = 0, 
  timestamp = 15007574, button = 0, child_has_focus = 1, click_child = 0, during_detach = 1, during_reorder = 0, 
  remove_in_detach = 0, focus_out = 0, has_scrolled = 0, in_child = 0, need_timer = 0, show_border = 0, show_tabs = 1, 
  scrollable = 1, tab_pos = 2, has_before_previous = 1, has_before_next = 0, has_after_previous = 0, 
  has_after_next = 1}