Merge branch 'wip/fix-double-greeters' into 'master'

don't start two greeters at startup

Closes #409

See merge request GNOME/gdm!28

2 files changed, 54 insertions, 12 deletions

diff --git a/daemon/gdm-local-display-factory.c b/daemon/gdm-local-display-factory.c
index 8bf92b64..82169ce4 100644
--- a/daemon/gdm-local-display-factory.c
+++ b/daemon/gdm-local-display-factory.c
@@ -552,8 +552,10 @@ maybe_stop_greeter_display (GdmDisplay *display)
 {
         g_autofree char *display_session_type = NULL;
 
-        if (gdm_display_get_status (display) != GDM_DISPLAY_MANAGED)
+        if (gdm_display_get_status (display) != GDM_DISPLAY_MANAGED) {
+                g_debug ("GdmLocalDisplayFactory: login window not in managed state, so ignoring");
                 return;
+        }
 
         g_object_get (G_OBJECT (display),
                       "session-type", &display_session_type,
@@ -561,9 +563,12 @@ maybe_stop_greeter_display (GdmDisplay *display)
 
         /* we can only stop greeter for wayland sessions, since
          * X server would jump back on exit */
-        if (g_strcmp0 (display_session_type, "wayland") != 0)
+        if (g_strcmp0 (display_session_type, "wayland") != 0) {
+                g_debug ("GdmLocalDisplayFactory: login window is running on Xorg, so ignoring");
                 return;
+        }
 
+        g_debug ("GdmLocalDisplayFactory: killing login window since its now unused");
         gdm_display_stop_greeter_session (display);
         gdm_display_unmanage (display);
         gdm_display_finish (display);
@@ -583,6 +588,7 @@ on_vt_changed (GIOChannel    *source,
         const char *session_type = NULL;
         int ret;
 
+        g_debug ("GdmLocalDisplayFactory: received VT change event");
         g_io_channel_seek_position (source, 0, G_SEEK_SET, NULL);
 
         if (condition & G_IO_PRI) {
@@ -604,21 +610,37 @@ on_vt_changed (GIOChannel    *source,
                 }
         }
 
-        if ((condition & G_IO_ERR) || (condition & G_IO_HUP))
+        if ((condition & G_IO_ERR) || (condition & G_IO_HUP)) {
+                g_debug ("GdmLocalDisplayFactory: kernel hung up active vt watch");
                 return G_SOURCE_REMOVE;
+        }
 
-        if (tty_of_active_vt == NULL)
+        if (tty_of_active_vt == NULL) {
+                g_debug ("GdmLocalDisplayFactory: unable to read active VT from kernel");
                 return G_SOURCE_CONTINUE;
+        }
 
         g_strchomp (tty_of_active_vt);
 
         /* don't do anything if we're on the same VT we were before */
-        if (g_strcmp0 (tty_of_active_vt, factory->priv->tty_of_active_vt) == 0)
+        if (g_strcmp0 (tty_of_active_vt, factory->priv->tty_of_active_vt) == 0) {
+                g_debug ("GdmLocalDisplayFactory: VT changed to the same VT, ignoring");
                 return G_SOURCE_CONTINUE;
+        }
 
         tty_of_previous_vt = g_steal_pointer (&factory->priv->tty_of_active_vt);
         factory->priv->tty_of_active_vt = g_steal_pointer (&tty_of_active_vt);
 
+        /* don't do anything at start up */
+        if (tty_of_previous_vt == NULL) {
+                g_debug ("GdmLocalDisplayFactory: VT is %s at startup",
+                         factory->priv->tty_of_active_vt);
+                return G_SOURCE_CONTINUE;
+        }
+
+        g_debug ("GdmLocalDisplayFactory: VT changed from %s to %s",
+                 tty_of_previous_vt, factory->priv->tty_of_active_vt);
+
         /* if the old VT was running a wayland login screen kill it
          */
         if (gdm_get_login_window_session_id ("seat0", &login_session_id)) {
@@ -630,10 +652,13 @@ on_vt_changed (GIOChannel    *source,
 
                         tty_of_login_window_vt = g_strdup_printf ("tty%u", vt);
 
+                        g_debug ("GdmLocalDisplayFactory: tty of login window is %s", tty_of_login_window_vt);
                         if (g_strcmp0 (tty_of_login_window_vt, tty_of_previous_vt) == 0) {
                                 GdmDisplayStore *store;
                                 GdmDisplay *display;
 
+                                g_debug ("GdmLocalDisplayFactory: VT switched from login window");
+
                                 store = gdm_display_factory_get_display_store (GDM_DISPLAY_FACTORY (factory));
                                 display = gdm_display_store_find (store,
                                                                   lookup_by_session_id,
@@ -641,6 +666,8 @@ on_vt_changed (GIOChannel    *source,
 
                                 if (display != NULL)
                                         maybe_stop_greeter_display (display);
+                        } else {
+                                g_debug ("GdmLocalDisplayFactory: VT not switched from login window");
                         }
                 }
         }
@@ -650,6 +677,7 @@ on_vt_changed (GIOChannel    *source,
          * jump to that login screen)
          */
         if (strcmp (factory->priv->tty_of_active_vt, tty_of_initial_vt) != 0) {
+                g_debug ("GdmLocalDisplayFactory: active VT is not initial VT, so ignoring");
                 return G_SOURCE_CONTINUE;
         }
 
@@ -660,13 +688,17 @@ on_vt_changed (GIOChannel    *source,
                 ret = sd_session_get_state (active_session_id, &state);
 
                 /* if there's something already running on the active VT then bail */
-                if (ret == 0 && g_strcmp0 (state, "closing") != 0)
+                if (ret == 0 && g_strcmp0 (state, "closing") != 0) {
+                        g_debug ("GdmLocalDisplayFactory: initial VT is in use, so ignoring");
                         return G_SOURCE_CONTINUE;
+                }
         }
 
         if (gdm_local_display_factory_use_wayland ())
                 session_type = "wayland";
 
+        g_debug ("GdmLocalDisplayFactory: creating new display on seat0 because of VT change");
+
         create_display (factory, "seat0", session_type, TRUE);
 
         return G_SOURCE_CONTINUE;
diff --git a/daemon/gdm-session-worker.c b/daemon/gdm-session-worker.c
index c1d89cab..d211cdb1 100644
--- a/daemon/gdm-session-worker.c
+++ b/daemon/gdm-session-worker.c
@@ -968,6 +968,8 @@ jump_to_vt (GdmSessionWorker  *worker,
 {
         int fd;
         int active_vt_tty_fd;
+        int active_vt = -1;
+        struct vt_stat vt_state = { 0 };
 
         g_debug ("GdmSessionWorker: jumping to VT %d", vt_number);
         active_vt_tty_fd = open ("/dev/tty0", O_RDWR | O_NOCTTY);
@@ -993,12 +995,20 @@ jump_to_vt (GdmSessionWorker  *worker,
 
         handle_terminal_vt_switches (worker, fd);
 
-        if (ioctl (fd, VT_ACTIVATE, vt_number) < 0) {
-                g_debug ("GdmSessionWorker: couldn't initiate jump to VT %d: %m",
-                         vt_number);
-        } else if (ioctl (fd, VT_WAITACTIVE, vt_number) < 0) {
-                g_debug ("GdmSessionWorker: couldn't finalize jump to VT %d: %m",
-                         vt_number);
+        if (ioctl (fd, VT_GETSTATE, &vt_state) <= 0) {
+                g_debug ("GdmSessionWorker: couldn't get current VT: %m");
+        } else {
+                active_vt = vt_state.v_active;
+        }
+
+        if (active_vt != vt_number) {
+                if (ioctl (fd, VT_ACTIVATE, vt_number) < 0) {
+                        g_debug ("GdmSessionWorker: couldn't initiate jump to VT %d: %m",
+                                 vt_number);
+                } else if (ioctl (fd, VT_WAITACTIVE, vt_number) < 0) {
+                        g_debug ("GdmSessionWorker: couldn't finalize jump to VT %d: %m",
+                                 vt_number);
+                }
         }
 
         close (active_vt_tty_fd);