From 070069d65e3b0d29e7a6db45310c900819d7d430 Mon Sep 17 00:00:00 2001
From: Antonio Scandurra <me@as-cii.com>
Date: Thu, 15 Apr 2021 18:12:56 +0200
Subject: [PATCH] Ensure top of cursor stack is either empty or a leaf node

Co-Authored-By: Nathan Sobo <nathan@zed.dev>
Co-Authored-By: Max Brunsfeld <max@zed.dev>
---
 zed/src/sum_tree/cursor.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/zed/src/sum_tree/cursor.rs b/zed/src/sum_tree/cursor.rs
index 440e99ba9025d3819b47d21982c5e8b1f510641b..4f6ec810554826970f7f71508005a71c4203a3e5 100644
--- a/zed/src/sum_tree/cursor.rs
+++ b/zed/src/sum_tree/cursor.rs
@@ -271,6 +271,7 @@ where
         }
 
         self.at_end = self.stack.is_empty();
+        debug_assert!(self.stack.is_empty() || self.stack.last().unwrap().tree.0.is_leaf());
     }
 
     pub fn descend_to_first_item<F>(&mut self, mut subtree: &'a SumTree<T>, filter_node: F)
@@ -656,6 +657,7 @@ where
         }
 
         self.at_end = self.stack.is_empty();
+        debug_assert!(self.stack.is_empty() || self.stack.last().unwrap().tree.0.is_leaf());
         if bias == SeekBias::Left {
             let mut end = self.seek_dimension.clone();
             if let Some(summary) = self.item_summary() {