[Spice-devel] [spice-gtk v4 2/2] gtk-session: clipboard: x11: owner-change improvement

[Victor Toso]

From: Victor Toso <me at victortoso.com>

On X11, the release-grab message might end up clearing the
GtkClipboard which triggers the owner-changed callback having the
event owner as NULL.

We should not be calling gtk_clipboard_request_targets() in this
situation as is prone to errors as the intention here is request
clipboard information from changes made by client OS.

The fix is to avoid any such request while spice client is holding the
keyboard grab.

Related: https://gitlab.freedesktop.org/spice/win32/vd_agent/issues/6
Related: https://gitlab.freedesktop.org/spice/linux/vd_agent/issues/9
Related: https://bugzilla.redhat.com/show_bug.cgi?id=1594876

Changed in v4:
- Updated commit log

Signed-off-by: Victor Toso <victortoso at redhat.com>
Tested-by: James Harvey @jamespharvey20
---
 src/spice-gtk-session.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/spice-gtk-session.c b/src/spice-gtk-session.c
index abce43f..20df70d 100644
--- a/src/spice-gtk-session.c
+++ b/src/spice-gtk-session.c
@@ -674,6 +674,19 @@ static void clipboard_owner_change(GtkClipboard        *clipboard,
         return;
     }
 
+#ifdef GDK_WINDOWING_X11
+    /* In X11, while holding the keyboard-grab we are not interested in this
+     * event as it either came by grab or release messages from agent.  */
+    if (GDK_IS_X11_DISPLAY(gdk_display_get_default()) &&
+        spice_gtk_session_get_keyboard_has_focus(self)) {
+        SPICE_DEBUG("clipboard: owner-changed event: not requesting client's target "
+                    "while holding focus");
+        return;
+    }
+#endif
+    SPICE_DEBUG("clipboard: owner-changed event: has-focus=%d",
+                spice_gtk_session_get_keyboard_has_focus(self));
+
     s->clipboard_by_guest[selection] = FALSE;
     s->clip_hasdata[selection] = TRUE;
     if (s->auto_clipboard_enable && !read_only(self))
-- 
2.20.1