vim-patch:8.2.4969: changing text in Visual mode may cause invalid memory access

Problem:    Changing text in Visual mode may cause invalid memory access.
Solution:   Check the Visual position after making a change.
https://github.com/vim/vim/commit/7ce5b2b590256ce53d6af28c1d203fb3bc1d2d97

1 files changed, 18 insertions, 0 deletions

diff --git a/src/nvim/cursor.c b/src/nvim/cursor.c
index 11c734479c..1446257f7e 100644
--- a/src/nvim/cursor.c
+++ b/src/nvim/cursor.c
@@ -399,6 +399,24 @@ void check_cursor(void)
   check_cursor_col();
 }
 
+/// Check if VIsual position is valid, correct it if not.
+/// Can be called when in Visual mode and a change has been made.
+void check_visual_pos(void)
+{
+  if (VIsual.lnum > curbuf->b_ml.ml_line_count) {
+    VIsual.lnum = curbuf->b_ml.ml_line_count;
+    VIsual.col = 0;
+    VIsual.coladd = 0;
+  } else {
+    int len = (int)STRLEN(ml_get(VIsual.lnum));
+
+    if (VIsual.col > len) {
+      VIsual.col = len;
+      VIsual.coladd = 0;
+    }
+  }
+}
+
 /// Make sure curwin->w_cursor is not on the NUL at the end of the line.
 /// Allow it when in Visual mode and 'selection' is not "old".
 void adjust_cursor_col(void)