[mutter/gnome-3-30] window-x11: Accept any focusable window as fallback focus

[Marco Trevisan <marcotrevi src gnome org>]

commit 03d880ad2b3492f427db3ac31894b1836f66cba3
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Wed Jul 3 11:15:36 2019 +0200

    window-x11: Accept any focusable window as fallback focus
    
    As per commit f71151a5 we were ignoring WM_TAKE_FOCUS-only windows as focus
    targets, however this might end-up in an infinite loop if there are multiple
    non-input windows stacked.
    
    So, accept any focusable window as fallback focus target even if it's a
    take-focus one (that might not reply to the request).
    
    Added a stacking test to verify this.
    
    Closes: https://gitlab.gnome.org/GNOME/mutter/issues/660
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/669
    
    (cherry picked from commit c327b2df95ff9979dd22bca2e0d285e1b3ba0add)

 src/Makefile-tests.am                              |  1 +
 .../closed-transient-no-input-parents.metatest     | 46 ++++++++++++++++++++++
 src/x11/window-x11.c                               |  2 +-
 3 files changed, 48 insertions(+), 1 deletion(-)
---
diff --git a/src/Makefile-tests.am b/src/Makefile-tests.am
index 7c1dd6040..195d1e47b 100644
--- a/src/Makefile-tests.am
+++ b/src/Makefile-tests.am
@@ -19,6 +19,7 @@ dist_stacking_DATA =                                          \
        $(srcdir)/tests/stacking/closed-transient-no-input-no-take-focus-parents.metatest       \
        $(srcdir)/tests/stacking/closed-transient-no-input-parent.metatest      \
        $(srcdir)/tests/stacking/closed-transient-no-input-parent-delayed-focus-default-cancelled.metatest    
  \
+       $(srcdir)/tests/stacking/closed-transient-no-input-parents.metatest     \
        $(srcdir)/tests/stacking/minimized.metatest     \
        $(srcdir)/tests/stacking/mixed-windows.metatest     \
        $(srcdir)/tests/stacking/set-parent.metatest    \
diff --git a/src/tests/stacking/closed-transient-no-input-parents.metatest 
b/src/tests/stacking/closed-transient-no-input-parents.metatest
new file mode 100644
index 000000000..e3ec2e84a
--- /dev/null
+++ b/src/tests/stacking/closed-transient-no-input-parents.metatest
@@ -0,0 +1,46 @@
+new_client 0 x11
+create 0/1
+show 0/1
+
+new_client 1 x11
+create 1/1
+show 1/1
+
+create 1/2 csd
+set_parent 1/2 1
+accept_focus 1/2 false
+show 1/2
+
+create 1/3 csd
+set_parent 1/3 2
+accept_focus 1/3 false
+show 1/3
+
+create 1/4 csd
+set_parent 1/4 3
+accept_focus 1/4 false
+show 1/4
+
+create 1/5 csd
+set_parent 1/5 3
+show 1/5
+
+wait
+assert_focused 1/5
+assert_stacking 0/1 1/1 1/2 1/3 1/4 1/5
+
+destroy 1/5
+dispatch
+
+assert_focused none
+assert_stacking 0/1 1/1 1/2 1/3 1/4
+
+sleep 250
+assert_focused none
+assert_stacking 0/1 1/1 1/2 1/3 1/4
+
+destroy 1/3
+wait
+
+assert_focused none
+assert_stacking 0/1 1/1 1/2 1/4
diff --git a/src/x11/window-x11.c b/src/x11/window-x11.c
index 18a97f373..325235f5d 100644
--- a/src/x11/window-x11.c
+++ b/src/x11/window-x11.c
@@ -865,7 +865,7 @@ meta_window_x11_focus (MetaWindow *window,
                       if (!focus_window)
                         break;
 
-                      if (focus_window->input)
+                      if (focus_window->input || focus_window->take_focus)
                         break;
 
                       if (focus_window->shaded && focus_window->frame)