add check for null pointer, avoid dereferencing

Signed-off-by: Thomas E. Dickey <dickey@invisible-island.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/Tree.c b/src/Tree.c
index 9be7a24..5c6fcd5 100644
--- a/src/Tree.c
+++ b/src/Tree.c
@@ -903,7 +903,7 @@ arrange_subtree(TreeWidget tree, Widget w, int depth, int x, int y)
     /*
      * now layout parent between first and last children
      */
-    if (relayout) {
+    if (relayout && (child != NULL)) {
 	Position adjusted;
 	TreeConstraints firstcc = TREE_CONSTRAINT (tc->tree.children[0]);
 	TreeConstraints lastcc = TREE_CONSTRAINT (child);