Merged own patch for the bug #391 (debugging and comments mostly).
diff --git a/lib/ChangeLog b/lib/ChangeLog
index ee32911..55ddfff 100644
--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,3 +1,7 @@
+2007-08-13 Denis Ovsienko
+
+	* zebra.h: introduce ZEBRA_ERR_KERNEL and ZEBRA_ERR_NOERROR
+
 2007-07-06 Atis Elsts <atis@mikrotik.com>
 
 	* pqueue.{c,h}: Export trickle_up
diff --git a/lib/zebra.h b/lib/zebra.h
index 2c7edd9..150aa2c 100644
--- a/lib/zebra.h
+++ b/lib/zebra.h
@@ -454,10 +454,12 @@
 #define ZEBRA_FAMILY_MAX                 3
 
 /* Error codes of zebra. */
+#define ZEBRA_ERR_NOERROR                0
 #define ZEBRA_ERR_RTEXIST               -1
 #define ZEBRA_ERR_RTUNREACH             -2
 #define ZEBRA_ERR_EPERM                 -3
 #define ZEBRA_ERR_RTNOEXIST             -4
+#define ZEBRA_ERR_KERNEL                -5
 
 /* Zebra message flags */
 #define ZEBRA_FLAG_INTERNAL           0x01