From 8abf18209ee9cc7579d7eaa61dbe57f07922f1fd Mon Sep 17 00:00:00 2001
From: Maxime Coste <mawww@kakoune.org>
Date: Sun, 5 Jul 2020 10:13:57 +1000
Subject: [PATCH] Fix selections getting unsorted on scroll

Fixes #3478
---
 src/input_handler.cc                     | 5 ++++-
 test/regression/3478-crash-on-scroll/cmd | 1 +
 test/regression/3478-crash-on-scroll/in  | 2 ++
 test/regression/3478-crash-on-scroll/out | 2 ++
 4 files changed, 9 insertions(+), 1 deletion(-)
 create mode 100644 test/regression/3478-crash-on-scroll/cmd
 create mode 100644 test/regression/3478-crash-on-scroll/in
 create mode 100644 test/regression/3478-crash-on-scroll/out

diff --git a/src/input_handler.cc b/src/input_handler.cc
index f13c513e..36425eff 100644
--- a/src/input_handler.cc
+++ b/src/input_handler.cc
@@ -1754,7 +1754,8 @@ void scroll_window(Context& context, LineCount offset, bool mouse_dragging)
 
     win_pos.line = clamp(win_pos.line + offset, 0_line, line_count-1);
 
-    Selection& main_selection = context.selections().main();
+    SelectionList& selections = context.selections();
+    Selection& main_selection = selections.main();
     const BufferCoord anchor = main_selection.anchor();
     const BufferCoord cursor = main_selection.cursor();
 
@@ -1775,6 +1776,8 @@ void scroll_window(Context& context, LineCount offset, bool mouse_dragging)
 
     window.set_position(win_pos);
     main_selection = { new_anchor, new_cursor };
+
+    selections.sort_and_merge_overlapping();
 }
 
 }
diff --git a/test/regression/3478-crash-on-scroll/cmd b/test/regression/3478-crash-on-scroll/cmd
new file mode 100644
index 00000000..f687bafe
--- /dev/null
+++ b/test/regression/3478-crash-on-scroll/cmd
@@ -0,0 +1 @@
+%sfoo<ret>(<pagedown>
diff --git a/test/regression/3478-crash-on-scroll/in b/test/regression/3478-crash-on-scroll/in
new file mode 100644
index 00000000..0d55bed3
--- /dev/null
+++ b/test/regression/3478-crash-on-scroll/in
@@ -0,0 +1,2 @@
+foo
+foo
diff --git a/test/regression/3478-crash-on-scroll/out b/test/regression/3478-crash-on-scroll/out
new file mode 100644
index 00000000..0d55bed3
--- /dev/null
+++ b/test/regression/3478-crash-on-scroll/out
@@ -0,0 +1,2 @@
+foo
+foo