Attempt to catch backtrace of segfault in bug #16234.

diff --git a/src/intervals.c b/src/intervals.c
index 0e3b684f570d7badb5bc514109d5e2f21bf76ce0..f2a2a16f4ad8606b167982b2490446b010a4dd6d 100644 (file)
--- a/src/intervals.c
+++ b/src/intervals.c
@@ -676,6 +676,7 @@ find_interval (register INTERVAL tree, register ptrdiff_t position)
 
   while (1)
     {
+      eassert (tree);
       if (relative_position < LEFT_TOTAL_LENGTH (tree))
        {
          tree = tree->left;