Correctly splice extmarks on tab with noexpandtab set

2 files changed, 73 insertions, 0 deletions

diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index cffa46fa77..b5d5d67e90 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -8764,6 +8764,10 @@ static bool ins_tab(void)
     getvcol(curwin, &fpos, &vcol, NULL, NULL);
     getvcol(curwin, cursor, &want_vcol, NULL, NULL);
 
+    // save start of changed region for extmark_splice
+    int start_row = fpos.lnum;
+    colnr_T start_col = fpos.col;
+
     // Use as many TABs as possible.  Beware of 'breakindent', 'showbreak'
     // and 'linebreak' adding extra virtual columns.
     while (ascii_iswhite(*ptr)) {
@@ -8813,6 +8817,11 @@ static bool ins_tab(void)
             replace_join(repl_off);
           }
         }
+        if (!(State & VREPLACE_FLAG)) {
+          extmark_splice_cols(curbuf, start_row - 1, start_col,
+                              cursor->col - start_col, fpos.col - start_col,
+                              kExtmarkUndo);
+        }
       }
       cursor->col -= i;
 
diff --git a/test/functional/lua/buffer_updates_spec.lua b/test/functional/lua/buffer_updates_spec.lua
index 7a6b5be8bc..8a25f4dc2d 100644
--- a/test/functional/lua/buffer_updates_spec.lua
+++ b/test/functional/lua/buffer_updates_spec.lua
@@ -666,6 +666,70 @@ describe('lua: nvim_buf_attach on_bytes', function()
       }
     end)
 
+    it("tab with noexpandtab and softtabstop", function()
+      command("set noet")
+      command("set ts=4")
+      command("set sw=2")
+      command("set sts=2")
+
+      local check_events = setup_eventcheck(verify, {'asdfasdf'})
+
+      feed("gg0i<tab>")
+
+      check_events {
+        { "test1", "bytes", 1, 3, 0, 0, 0, 0, 0, 0, 0, 1, 1 },
+        { "test1", "bytes", 1, 4, 0, 1, 1, 0, 0, 0, 0, 1, 1 },
+      }
+      feed("<tab>")
+
+      -- when spaces are merged into a tabstop
+      check_events {
+        { "test1", "bytes", 1, 5, 0, 2, 2, 0, 0, 0, 0, 1, 1 },
+        { "test1", "bytes", 1, 6, 0, 3, 3, 0, 0, 0, 0, 1, 1 },
+        { "test1", "bytes", 1, 7, 0, 0, 0, 0, 4, 4, 0, 1, 1 },
+      }
+
+      feed("<esc>u")
+      check_events {
+        { "test1", "bytes", 1, 8, 0, 0, 0, 0, 1, 1, 0, 4, 4 },
+        { "test1", "bytes", 1, 8, 0, 0, 0, 0, 4, 4, 0, 0, 0 }
+      }
+
+      -- in REPLACE mode
+      feed("R<tab><tab>")
+      check_events {
+        { "test1", "bytes", 1, 9, 0, 0, 0, 0, 1, 1, 0, 1, 1 },
+        { "test1", "bytes", 1, 10, 0, 1, 1, 0, 0, 0, 0, 1, 1 },
+        { "test1", "bytes", 1, 11, 0, 2, 2, 0, 1, 1, 0, 1, 1 },
+        { "test1", "bytes", 1, 12, 0, 3, 3, 0, 0, 0, 0, 1, 1 },
+        { "test1", "bytes", 1, 13, 0, 0, 0, 0, 4, 4, 0, 1, 1 },
+      }
+      feed("<esc>u")
+      check_events {
+        { "test1", "bytes", 1, 14, 0, 0, 0, 0, 1, 1, 0, 4, 4 },
+        { "test1", "bytes", 1, 14, 0, 2, 2, 0, 2, 2, 0, 1, 1 },
+        { "test1", "bytes", 1, 14, 0, 0, 0, 0, 2, 2, 0, 1, 1 }
+      }
+
+      -- in VISUALREPLACE mode
+      feed("gR<tab><tab>")
+      check_events {
+          { "test1", "bytes", 1, 15, 0, 0, 0, 0, 1, 1, 0, 1, 1 };
+          { "test1", "bytes", 1, 16, 0, 1, 1, 0, 1, 1, 0, 1, 1 };
+          { "test1", "bytes", 1, 17, 0, 2, 2, 0, 1, 1, 0, 1, 1 };
+          { "test1", "bytes", 1, 18, 0, 3, 3, 0, 1, 1, 0, 1, 1 };
+          { "test1", "bytes", 1, 19, 0, 3, 3, 0, 1, 1, 0, 0, 0 };
+          { "test1", "bytes", 1, 20, 0, 3, 3, 0, 0, 0, 0, 1, 1 };
+          { "test1", "bytes", 1, 22, 0, 2, 2, 0, 1, 1, 0, 0, 0 };
+          { "test1", "bytes", 1, 23, 0, 2, 2, 0, 0, 0, 0, 1, 1 };
+          { "test1", "bytes", 1, 25, 0, 1, 1, 0, 1, 1, 0, 0, 0 };
+          { "test1", "bytes", 1, 26, 0, 1, 1, 0, 0, 0, 0, 1, 1 };
+          { "test1", "bytes", 1, 28, 0, 0, 0, 0, 1, 1, 0, 0, 0 };
+          { "test1", "bytes", 1, 29, 0, 0, 0, 0, 0, 0, 0, 1, 1 };
+          { "test1", "bytes", 1, 31, 0, 0, 0, 0, 4, 4, 0, 1, 1 };
+      }
+    end)
+
     it("sends events when undoing with undofile", function()
       write_file("Xtest-undofile", dedent([[
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