Correct mem corruption if position filter used before arc or polygon filter.

diff --git a/position.c b/position.c
index 9105dfff0a2183dc27d08d0c498af1e4c87f644b..85125786744810f0f7448ef269489a4cf27dfe21 100644 (file)
--- a/position.c
+++ b/position.c
@@ -321,6 +321,7 @@ radius_process(void)
                waypoint * wp = comp[i];
                waypt_add(wp);
                xfree(wp->extra_data);
+               wp->extra_data = NULL;
        }
 
        xfree(comp);