From 320e9c1c21817fd76b84345018661f70437fa4b5 Mon Sep 17 00:00:00 2001
From: Luuk van Baal <luukvbaal@gmail.com>
Date: Wed, 13 Dec 2023 23:30:19 +0100
Subject: [PATCH] fix(extmark): only invalidate unpaired marks on deleted rows

Problem:  Unpaired marks are invalidated if its column is deleted,
          which may just be a "placeholder" column, e.g. for signs.
Solution: Only remove unpaired marks if its entire row is deleted.
---
 src/nvim/extmark.c               | 10 +++++++---
 test/functional/ui/sign_spec.lua | 23 +++++++++++++----------
 2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/src/nvim/extmark.c b/src/nvim/extmark.c
index 92fbc6fb79..f914137ccc 100644
--- a/src/nvim/extmark.c
+++ b/src/nvim/extmark.c
@@ -332,9 +332,13 @@ void extmark_splice_delete(buf_T *buf, int l_row, colnr_T l_col, int u_row, coln
       if (endpos.row < 0) {
         endpos = mark.pos;
       }
-      if ((endpos.col <= u_col || (!u_col && endpos.row == mark.pos.row))
-          && mark.pos.col >= l_col
-          && mark.pos.row >= l_row && endpos.row <= u_row - (u_col ? 0 : 1)) {
+      // Invalidate unpaired marks in deleted lines and paired marks whose entire
+      // range has been deleted.
+      if ((!mt_paired(mark) && mark.pos.row < u_row)
+          || (mt_paired(mark)
+              && (endpos.col <= u_col || (!u_col && endpos.row == mark.pos.row))
+              && mark.pos.col >= l_col
+              && mark.pos.row >= l_row && endpos.row <= u_row - (u_col ? 0 : 1))) {
         if (mt_no_undo(mark)) {
           extmark_del(buf, itr, mark, true);
           continue;
diff --git a/test/functional/ui/sign_spec.lua b/test/functional/ui/sign_spec.lua
index bf2830f2f0..316d3fe3ac 100644
--- a/test/functional/ui/sign_spec.lua
+++ b/test/functional/ui/sign_spec.lua
@@ -218,14 +218,15 @@ describe('Signs', function()
       ]])
       -- "auto:3" accommodates all the signs we defined so far.
       command('set signcolumn=auto:3')
-      screen:expect([[
+      local s3 = [[
         {1:>>}{8:XX}{2:  }{6:  1 }a                                          |
         {8:XX}{1:>>}{2:  }{6:  2 }b                                          |
         {8:XX}{1:>>}WW{6:  3 }c                                          |
         {2:      }{6:  4 }^                                           |
         {0:~                                                    }|*9
                                                              |
-      ]])
+      ]]
+      screen:expect(s3)
       -- Check "yes:9".
       command('set signcolumn=yes:9')
       screen:expect([[
@@ -239,14 +240,7 @@ describe('Signs', function()
       -- Check "auto:N" larger than the maximum number of signs defined in
       -- a single line (same result as "auto:3").
       command('set signcolumn=auto:4')
-      screen:expect{grid=[[
-        {1:>>}{8:XX}{2:  }{6:  1 }a                                          |
-        {8:XX}{1:>>}{2:  }{6:  2 }b                                          |
-        {8:XX}{1:>>}WW{6:  3 }c                                          |
-        {2:      }{6:  4 }^                                           |
-        {0:~                                                    }|*9
-                                                             |
-      ]]}
+      screen:expect(s3)
       -- line deletion deletes signs.
       command('3move1')
       command('2d')
@@ -257,6 +251,15 @@ describe('Signs', function()
         {0:~                                                    }|*10
                                                              |
       ]])
+      -- character deletion does not delete signs.
+      feed('x')
+      screen:expect([[
+        {1:>>}{8:XX}{6:  1 }a                                            |
+        {8:XX}{1:>>}{6:  2 }^                                             |
+        {2:    }{6:  3 }                                             |
+        {0:~                                                    }|*10
+                                                             |
+      ]])
     end)
 
     it('auto-resize sign column with minimum size (#13783)', function()