[Spice-devel] [PATCH] spicec-x11: Fix going into a never ending loop upon xrandr event (#628573) (v2)

[Hans de Goede]

When handling an xrandr event the event_listener->on_monitors_change()
callback destroys and re-creates the monitor object(s) which results
in the DynamicScreen or MultyMonconstructor being called, which triggers
more xrandr events. This causes a never ending event handling loop making
spicec hang, and eventually making the X-server crash as a backlog
of events builds up and it oom's.

This patches this by explictly processing the xrandr event caused
by the constructor inside the constructor surrounded by the already
present guard code against recursive xrandr events.
---
 client/x11/platform.cpp |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/client/x11/platform.cpp b/client/x11/platform.cpp
index 8292d44..cc1502b 100644
--- a/client/x11/platform.cpp
+++ b/client/x11/platform.cpp
@@ -778,6 +778,11 @@ DynamicScreen::DynamicScreen(Display* display, int screen, int& next_mon_id)
     platform_win = XCreateSimpleWindow(display, RootWindow(display, screen), 0, 0, 1, 1, 0, 0, 0);
     XSelectInput(display, platform_win, StructureNotifyMask);
     XRRSelectInput(display, platform_win, RRScreenChangeNotifyMask);
+
+    Monitor::self_monitors_change++;
+    process_monitor_configure_events(platform_win);
+    Monitor::self_monitors_change--;
+
     XPlatform::set_win_proc(platform_win, root_win_proc);
     intern_clipboard_atoms();
     X_DEBUG_SYNC(display);
@@ -1046,6 +1051,11 @@ MultyMonScreen::MultyMonScreen(Display* display, int screen, int& next_mon_id)
     X_DEBUG_SYNC(get_display());
     intern_clipboard_atoms();
     XPlatform::set_win_proc(root_window, root_win_proc);
+
+    XMonitor::inc_change_ref();
+    process_monitor_configure_events(root_window);
+    XMonitor::dec_change_ref();
+
     X_DEBUG_SYNC(get_display());
     //
     //platform_win = XCreateSimpleWindow(display, RootWindow(display, screen), 0, 0, 1, 1, 0, 0, 0);
-- 
1.7.2.2