Commit 100% working part of patch from Laurent Rabret ([quagga-dev 830]).
Also tiny temporary fix from me to spf thread crash. Will look at it later.
diff --git a/isisd/isis_spf.c b/isisd/isis_spf.c
index 03f724f..1987e0d 100644
--- a/isisd/isis_spf.c
+++ b/isisd/isis_spf.c
@@ -1037,7 +1037,9 @@
     spftree->pending = 1;
     return retval;
   }
-  THREAD_TIMER_OFF(spftree->t_spf_periodic);
+  /* FIXME: This stuff is just mess. All spf thread add/cancel
+     logic should be reviewed. */
+  /* THREAD_TIMER_OFF(spftree->t_spf_periodic); */
 
   if (diff < MINIMUM_SPF_INTERVAL) {
     if (level == 1)