core: Make sure focus_default_window() worked

The function focus_default_window() optionally takes a MetaWindow
argument denoting a window that should not be focused.

That function calls focus_ancestor_or_top_window() which in turn
calls meta_window_focus() to pass focus to another window.

However meta_window_focus() gives no guarantee that the given window
will end up being the one focused, and can fail in various and creative
ways.

If that fails, we could possibly end up with the focus window being the
one to avoid, while the caller assumes focus was changed, going as far
as asserting that fact like meta_window_unmanage() does.

As a result, mutter may abort simply because meta_window_focus() failed
to set focus on the expected window.

To avoid that issue, check that the focus did not end up on the window
that we explicitly did not want, and if that's the case, simply fallback
to the default focus window.

Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/862
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1643>
This commit is contained in:
Olivier Fourdan 2020-12-16 16:51:24 +01:00 committed by Marge Bot
parent 46ec29458d
commit afa431547b

View File

@ -1357,6 +1357,30 @@ find_focusable_ancestor (MetaWindow *window,
return TRUE; return TRUE;
} }
static gboolean
try_to_set_focus_and_check (MetaWindow *window,
MetaWindow *not_this_one,
uint32_t timestamp)
{
meta_window_focus (window, timestamp);
/* meta_window_focus() does not guarantee that focus will end up
* where we expect, it can fail for various reasons, better check
* it did not actually changed or even left focus to the window we
* explicitly want to avoid.
*/
if (not_this_one &&
meta_display_get_focus_window (window->display) == not_this_one)
{
meta_warning ("Failed to focus window %s while avoiding %s",
window->desc, not_this_one->desc);
return FALSE;
}
return TRUE;
}
/* Focus ancestor of not_this_one if there is one */ /* Focus ancestor of not_this_one if there is one */
static void static void
focus_ancestor_or_top_window (MetaWorkspace *workspace, focus_ancestor_or_top_window (MetaWorkspace *workspace,
@ -1390,8 +1414,8 @@ focus_ancestor_or_top_window (MetaWorkspace *workspace,
"Focusing %s, ancestor of %s", "Focusing %s, ancestor of %s",
ancestor->desc, not_this_one->desc); ancestor->desc, not_this_one->desc);
meta_window_focus (ancestor, timestamp); if (try_to_set_focus_and_check (ancestor, not_this_one, timestamp))
{
/* Also raise the window if in click-to-focus */ /* Also raise the window if in click-to-focus */
if (meta_prefs_get_focus_mode () == G_DESKTOP_FOCUS_MODE_CLICK) if (meta_prefs_get_focus_mode () == G_DESKTOP_FOCUS_MODE_CLICK)
meta_window_raise (ancestor); meta_window_raise (ancestor);
@ -1399,6 +1423,7 @@ focus_ancestor_or_top_window (MetaWorkspace *workspace,
return; return;
} }
} }
}
window = meta_stack_get_default_focus_window (workspace->display->stack, window = meta_stack_get_default_focus_window (workspace->display->stack,
workspace, workspace,
@ -1408,19 +1433,19 @@ focus_ancestor_or_top_window (MetaWorkspace *workspace,
{ {
meta_topic (META_DEBUG_FOCUS, meta_topic (META_DEBUG_FOCUS,
"Focusing workspace MRU window %s", window->desc); "Focusing workspace MRU window %s", window->desc);
if (try_to_set_focus_and_check (window, not_this_one, timestamp))
meta_window_focus (window, timestamp); {
/* Also raise the window if in click-to-focus */ /* Also raise the window if in click-to-focus */
if (meta_prefs_get_focus_mode () == G_DESKTOP_FOCUS_MODE_CLICK) if (meta_prefs_get_focus_mode () == G_DESKTOP_FOCUS_MODE_CLICK)
meta_window_raise (window); meta_window_raise (window);
return;
} }
else }
{
meta_topic (META_DEBUG_FOCUS, meta_topic (META_DEBUG_FOCUS,
"No MRU window to focus found; focusing no_focus_window."); "No MRU window to focus found; focusing no_focus_window.");
meta_display_unset_input_focus (workspace->display, timestamp); meta_display_unset_input_focus (workspace->display, timestamp);
}
} }
/** /**