Linux: fix crash in Firefox at plugin unload time when more than one O3D instance is running. The problem here was that Firefox has a bug where closing a tab actually deletes the parent windows of the plugin _before_ calling NPP_Destroy(), and Gtk recursively destroys all children automatically. Hence, once NPP_Destroy() runs our X11 Window handle is already invalid. If there is another O3D instance running in the same browser process, then performing the TearDown() call requires a MakeCurrent() call on the Window handle, which will fail with GLXBadDrawable and kill the browser. The solution requires two things. First, to avoid Gtk recursively destroying the children, we explicitly open a separate X11 connection for our GtkPlug, which means a destroy on the parents does not automatically propagate to the children because it has to go through the X server first. Second, we register a callback with our GtkPlug to handle this event from the X server by turning our GtkPlug into a hidden unparented window rather than destroying it.

Unrelatedly, also make fullscreen windows be set_keep_above and fix some spurious unref() calls (which produced warnings but otherwise were mostly harmless).

TEST=opening and closing concurrent ping pong windows in FF and Chrome (64-bit)

Review URL: http://codereview.chromium.org/553028

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@36650 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 21 insertions, 7 deletions

diff --git a/o3d/plugin/cross/o3d_glue.cc b/o3d/plugin/cross/o3d_glue.cc
index 1914ac8..18b31c6 100644
--- a/o3d/plugin/cross/o3d_glue.cc
+++ b/o3d/plugin/cross/o3d_glue.cc
@@ -144,6 +144,7 @@ PluginObject::PluginObject(NPP npp)
       xt_interval_(0),
       last_click_time_(0),
       drawable_(0),
+      gdk_display_(NULL),
       gtk_container_(NULL),
       gtk_fullscreen_container_(NULL),
       gtk_event_source_(NULL),
diff --git a/o3d/plugin/cross/o3d_glue.h b/o3d/plugin/cross/o3d_glue.h
index 2375173..d732c13 100644
--- a/o3d/plugin/cross/o3d_glue.h
+++ b/o3d/plugin/cross/o3d_glue.h
@@ -291,6 +291,7 @@ class PluginObject: public NPObject {
 
   // XEmbed mode
   Window drawable_;
+  GdkDisplay *gdk_display_;
   GtkWidget *gtk_container_;
   GtkWidget *gtk_fullscreen_container_;
   GtkWidget *gtk_event_source_;
diff --git a/o3d/plugin/linux/main_linux.cc b/o3d/plugin/linux/main_linux.cc
index 9162a91..2b3e89e 100644
--- a/o3d/plugin/linux/main_linux.cc
+++ b/o3d/plugin/linux/main_linux.cc
@@ -718,6 +718,8 @@ NPError NPP_Destroy(NPP instance, NPSavedData **save) {
   HANDLE_CRASHES;
   PluginObject *obj = static_cast<PluginObject*>(instance->pdata);
   if (obj) {
+    obj->TearDown();
+
     if (obj->xt_widget_) {
       // NOTE: This crashes. Not sure why, possibly the widget has
       // already been destroyed, but we haven't received a SetWindow(NULL).
@@ -735,24 +737,24 @@ NPError NPP_Destroy(NPP instance, NPSavedData **save) {
     }
     if (obj->gtk_container_) {
       gtk_widget_destroy(obj->gtk_container_);
-      gtk_widget_unref(obj->gtk_container_);
       obj->gtk_container_ = NULL;
     }
     if (obj->gtk_fullscreen_container_) {
       gtk_widget_destroy(obj->gtk_fullscreen_container_);
-      gtk_widget_unref(obj->gtk_fullscreen_container_);
-      obj->gtk_container_ = NULL;
+      obj->gtk_fullscreen_container_ = NULL;
+    }
+    if (obj->gdk_display_) {
+      gdk_display_close(obj->gdk_display_);
+      obj->gdk_display_ = NULL;
     }
     obj->gtk_event_source_ = NULL;
     obj->event_handler_id_ = 0;
     obj->window_ = 0;
     obj->drawable_ = 0;
 
-    obj->TearDown();
     NPN_ReleaseObject(obj);
     instance->pdata = NULL;
   }
-
   return NPERR_NO_ERROR;
 }
 
@@ -769,7 +771,17 @@ NPError NPP_SetWindow(NPP instance, NPWindow *window) {
     if (g_xembed_support) {
       // We asked for a XEmbed plugin, the xwindow is a GtkSocket, we create
       // a GtkPlug to go into it.
-      obj->gtk_container_ = gtk_plug_new(xwindow);
+      obj->gdk_display_ = gdk_display_open(XDisplayString(display));
+      LOG_ASSERT(obj->gdk_display_) << "Unable to open X11 display";
+      display = GDK_DISPLAY_XDISPLAY(obj->gdk_display_);
+      obj->gtk_container_ =
+          gtk_plug_new_for_display(obj->gdk_display_, xwindow);
+      // Firefox has a bug where it sometimes destroys our parent widget before
+      // calling NPP_Destroy. We handle this by hiding our X window instead of
+      // destroying it. Without this, future OpenGL calls can raise a
+      // GLXBadDrawable error and kill the browser process.
+      g_signal_connect(G_OBJECT(obj->gtk_container_), "delete-event",
+                       G_CALLBACK(gtk_widget_hide_on_delete), NULL);
       gtk_widget_set_double_buffered(obj->gtk_container_, FALSE);
       if (!obj->fullscreen()) {
         obj->SetGtkEventSource(obj->gtk_container_);
@@ -921,6 +933,7 @@ bool PluginObject::RequestFullscreenDisplay() {
   // Stops Gtk from writing an off-screen buffer to the display, which conflicts
   // with our GL rendering.
   gtk_widget_set_double_buffered(widget, FALSE);
+  gtk_window_set_keep_above(window, TRUE);
   GdkScreen *screen = gtk_window_get_screen(window);
   // In the case of Xinerama or TwinView, these will be the dimensions of the
   // whole desktop, which is wrong, but the window manager is smart enough to
@@ -961,7 +974,6 @@ void PluginObject::CancelFullscreenDisplay() {
                             false);
   SetGtkEventSource(gtk_container_);
   gtk_widget_destroy(gtk_fullscreen_container_);
-  gtk_widget_unref(gtk_fullscreen_container_);
   gtk_fullscreen_container_ = NULL;
   fullscreen_window_ = 0;
   fullscreen_ = false;