gdm/gdm-vt-allocation-hack.patch

Index: gdm-2.31.2/daemon/gdm-server.c
===================================================================
--- gdm-2.31.2.orig/daemon/gdm-server.c
+++ gdm-2.31.2/daemon/gdm-server.c
@@ -33,6 +33,8 @@
 #include <grp.h>
 #include <signal.h>
 #include <sys/resource.h>
+#include <sys/ioctl.h>
+#include <sys/vt.h>
 
 #ifdef HAVE_SYS_PRCTL_H
 #include <sys/prctl.h>
@@ -154,6 +156,92 @@ _gdm_server_query_ck_for_display_device
         return out;
 }
 
+#ifndef O_NOCTTY
+# define O_NOCTTY 0
+#endif
+
+static int
+open_vt (int vtno)
+{
+	char *vtname;
+	int fd;
+
+	vtname = g_strdup_printf ("/dev/tty%d", vtno);
+
+	do {
+		errno = 0;
+		fd = open (vtname, O_RDWR | O_NOCTTY, 0);
+	} while (errno == EINTR);
+
+	g_free (vtname);
+	return fd;
+}
+
+static gint
+find_first_probably_free_vt (void)
+{
+	int fd, fdv;
+	int vtno;
+	unsigned short vtmask;
+	struct vt_stat vtstat;
+	guint v_state;
+
+	fdv = -1;
+
+	do {
+		errno = 0;
+		fd = open ("/dev/console", O_WRONLY | O_NOCTTY, 0);
+	} while (errno == EINTR);
+
+	if (fd >= 0) {
+		if (ioctl (fd, VT_GETSTATE, &vtstat) >= 0) {
+			v_state = vtstat.v_state;
+		} else {
+			close (fd);
+			v_state = 0;
+			fd = -1;
+		}
+	} else {
+		v_state = 0;
+	}
+
+	if (fd < 0) {
+		do {
+			errno = 0;
+			fd = open ("/dev/console", O_RDONLY | O_NOCTTY, 0);
+		} while (errno == EINTR);
+
+		if (fd >= 0) {
+			if (ioctl (fd, VT_GETSTATE, &vtstat) >= 0)
+				v_state = vtstat.v_state;
+		}
+	}
+
+	for (vtno = 7, vtmask = 1 << vtno; vtmask; vtno++, vtmask <<= 1) {
+		/* Is this console in use? */
+		if (v_state & vtmask)
+			continue;
+
+		/* No, try to open it */
+		fdv = open_vt (vtno);
+		if (fdv >= 0)
+			break;
+
+		/* If we're here, kernel indicated that the console was free,
+		 * but we failed to open it. Just go on to higher VTs. */
+	}
+
+        if (fdv >= 0)
+                close (fdv);
+        else
+		vtno = -1;
+
+	if (fd >= 0)
+		close (fd);
+
+	return vtno;
+}
+
 char *
 gdm_server_get_display_device (GdmServer *server)
 {
@@ -314,6 +402,11 @@ gdm_server_resolve_command_line (GdmServ
 
         if (vtarg != NULL && ! gotvtarg) {
                 argv[len++] = g_strdup (vtarg);
+        } else if (!query_in_arglist && !gotvtarg) {
+                gint vtnum = find_first_probably_free_vt ();
+
+                if (vtnum > 0)
+                        argv [len++] = g_strdup_printf ("vt%d", vtnum);
         }
 
         argv[len++] = NULL;