From 264631c4c1bace2b6a67293d9635504db1378464 Mon Sep 17 00:00:00 2001
From: Jan Edmund Lazo <janedmundlazo@hotmail.com>
Date: Sun, 21 Jun 2026 20:27:50 -0400
Subject: [PATCH] vim-patch:8.2.1888: Vim9: getbufline(-1, 1, '$') gives an
 error

Problem:    Vim9: Getbufline(-1, 1, '$') gives an error.
Solution:   Return an empty list. (closes vim/vim#7180)

https://github.com/vim/vim/commit/e6e70a10f118ecfa9df2425e8724bc009bd09929

Co-authored-by: Bram Moolenaar <Bram@vim.org>
---
 src/nvim/eval/buffer.c                           | 16 ++++++++++------
 test/functional/vimscript/buf_functions_spec.lua |  4 ++++
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/nvim/eval/buffer.c b/src/nvim/eval/buffer.c
index 4ee6b39698..df9b37af58 100644
--- a/src/nvim/eval/buffer.c
+++ b/src/nvim/eval/buffer.c
@@ -714,15 +714,19 @@ static void get_buffer_lines(buf_T *buf, linenr_T start, linenr_T end, bool retl
 ///                 false: "getbufoneline()" function
 static void getbufline(typval_T *argvars, typval_T *rettv, bool retlist)
 {
+  linenr_T lnum = 1;
+  linenr_T end = 1;
   const int did_emsg_before = did_emsg;
   buf_T *const buf = tv_get_buf_from_arg(&argvars[0]);
-  const linenr_T lnum = tv_get_lnum_buf(&argvars[1], buf);
-  if (did_emsg > did_emsg_before) {
-    return;
+  if (buf != NULL) {
+    lnum = tv_get_lnum_buf(&argvars[1], buf);
+    if (did_emsg > did_emsg_before) {
+      return;
+    }
+    end = (argvars[2].v_type == VAR_UNKNOWN
+           ? lnum
+           : tv_get_lnum_buf(&argvars[2], buf));
   }
-  const linenr_T end = (argvars[2].v_type == VAR_UNKNOWN
-                        ? lnum
-                        : tv_get_lnum_buf(&argvars[2], buf));
 
   get_buffer_lines(buf, lnum, end, retlist, rettv);
 }
diff --git a/test/functional/vimscript/buf_functions_spec.lua b/test/functional/vimscript/buf_functions_spec.lua
index a4389ca97a..d2907cd22b 100644
--- a/test/functional/vimscript/buf_functions_spec.lua
+++ b/test/functional/vimscript/buf_functions_spec.lua
@@ -191,11 +191,15 @@ describe('getbufline() function', function()
   end)
   it('returns empty list when range is invalid', function()
     eq({}, fn.getbufline(1, 0))
+    eq({}, fn.getbufline(-1, 1, '$'))
+    eq({}, fn.getbufline(-1, '$', '$'))
     api.nvim_buf_set_lines(0, 0, 1, false, { 'foo', 'bar', 'baz' })
     eq({}, fn.getbufline(1, 2, 1))
     eq({}, fn.getbufline(1, -10, -20))
     eq({}, fn.getbufline(1, -2, -1))
     eq({}, fn.getbufline(1, -1, 9999))
+    eq({}, fn.getbufline(-1, 1, '$'))
+    eq({}, fn.getbufline(-1, '$', '$'))
   end)
   it('returns expected lines', function()
     api.nvim_set_option_value('hidden', true, {})