From 90df4320b7c10e3b81d979d57b4a39ee1b0a574e Mon Sep 17 00:00:00 2001
From: Maxime Coste <frrrwww@gmail.com>
Date: Wed, 10 Sep 2014 13:41:32 +0100
Subject: [PATCH] Add a small validation assert to catch a rare bug

---
 src/line_modification.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/line_modification.cc b/src/line_modification.cc
index 5da287fc..62c76243 100644
--- a/src/line_modification.cc
+++ b/src/line_modification.cc
@@ -92,6 +92,9 @@ std::vector<LineModification> compute_line_modifications(const Buffer& buffer, s
                 modif.new_line + modif.num_added - change.pos;
             const LineCount num_removed_from_added =
                 std::min(num_removed, num_added_after_pos);
+
+            kak_assert(modif.num_added >= num_removed_from_added);
+
             modif.num_added -= num_removed_from_added;
             modif.num_removed += num_removed - num_removed_from_added;