countnode234() should politely return 0 when passed NULL. Was

breaking delpos234(empty_tree, 0).

git-svn-id: svn://svn.tartarus.org/sgt/putty@1054 cda61777-01e9-0310-a592-d414129be87e

diff --git a/tree234.c b/tree234.c
index 1f02670..1aac3a6 100644 (file)
--- a/tree234.c
+++ b/tree234.c
@@ -90,6 +90,8 @@ void freetree234(tree234 *t) {
 static int countnode234(node234 *n) {
     int count = 0;
     int i;
+    if (!n)
+       return 0;
     for (i = 0; i < 4; i++)
        count += n->counts[i];
     for (i = 0; i < 3; i++)