Commit: runtime(vim): Fix heredoc triggering misidentifcation of Vim9 script

[Christian Brabandt]

runtime(vim): Fix heredoc triggering misidentifcation of Vim9 script

Commit: https://github.com/vim/vim/commit/9a899af7e8e74bb094cfdfda857580b2e8ddf840
Author: Doug Kearns <dougk...@gmail.com>
Date: Sun Jun 28 17:22:16 2026 +0000

runtime(vim): Fix heredoc triggering misidentifcation of Vim9 script

The following let-heredoc can cause legacy scripts to be misidentified
as Vim9 script if it appears early in the file. Only match :vim9script
at the start of a line where it sensibly belongs.

let x =<< trim LINES
vim9script
...
LINES

fixes: #20647 (reported by Maxim Kim).
closes: #20654

Signed-off-by: Doug Kearns <dougk...@gmail.com>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/runtime/ftplugin/vim.vim b/runtime/ftplugin/vim.vim
index 21ca040fa..b54cb48f0 100644
--- a/runtime/ftplugin/vim.vim
+++ b/runtime/ftplugin/vim.vim
@@ -6,7 +6,7 @@
" @Konfekt
" @tpope (s:Help())
" @lacygoill
-" Last Change: 2026 May 31
+" Last Change: 2026 Jun 27

" Only do this when not done yet for this buffer
if exists("b:did_ftplugin")
@@ -107,7 +107,7 @@ command! -buffer -nargs=1 VimKeywordPrg :exe 'help' s:Help(<q-args>)
setlocal keywordprg=:VimKeywordPrg

" Comments starts with # in Vim9 script. We have to guess which one to use.
-if "
" .. getline(1, 32)->join("
") =~# '
\s*vim9\%[script]\>'
+if "
" .. getline(1, 32)->join("
") =~# '
vim9s\%[cript]\>'
setlocal commentstring=#\ %s
" Set 'comments' to format dashed lists in comments, for Vim9 script.
setlocal com=sO:#\ -,mO:#\ \ ,eO:##,:#\\ ,:#
diff --git a/runtime/syntax/generator/vim.vim.base b/runtime/syntax/generator/vim.vim.base
index 309ef2a9b..5b20d1ddf 100644
--- a/runtime/syntax/generator/vim.vim.base
+++ b/runtime/syntax/generator/vim.vim.base
@@ -2,7 +2,7 @@
" Language: Vim script
" Maintainer: Hirohito Higashi <h.east.727 ATMARK gmail.com>
" Doug Kearns <dougk...@gmail.com>
-" Last Change: 2026 Jun 12
+" Last Change: 2026 Jun 27
" Former Maintainer: Charles E. Campbell

" DO NOT CHANGE DIRECTLY.
@@ -19,7 +19,7 @@ set cpo&vim
" Feature testing {{{1

" NOTE: vimsyn_force_vim9 for internal use only
-let s:vim9script = get(b:, "vimsyn_force_vim9", v:false) || "
" .. getline(1, 32)->join("
") =~# '
\s*vim9\%[script]\>'
+let s:vim9script = get(b:, "vimsyn_force_vim9", v:false) || "
" .. getline(1, 32)->join("
") =~# '
vim9s\%[cript]\>'

function s:has(feature)
return has(a:feature) || index(get(g:, "vimsyn_vim_features", []), a:feature) != -1
diff --git a/runtime/syntax/vim.vim b/runtime/syntax/vim.vim
index 08d2a2b85..60e584dcc 100644
--- a/runtime/syntax/vim.vim
+++ b/runtime/syntax/vim.vim
@@ -2,7 +2,7 @@
" Language: Vim script
" Maintainer: Hirohito Higashi <h.east.727 ATMARK gmail.com>
" Doug Kearns <dougk...@gmail.com>
-" Last Change: 2026 Jun 12
+" Last Change: 2026 Jun 27
" Former Maintainer: Charles E. Campbell

" DO NOT CHANGE DIRECTLY.
@@ -19,7 +19,7 @@ set cpo&vim
" Feature testing {{{1

" NOTE: vimsyn_force_vim9 for internal use only
-let s:vim9script = get(b:, "vimsyn_force_vim9", v:false) || "
" .. getline(1, 32)->join("
") =~# '
\s*vim9\%[script]\>'
+let s:vim9script = get(b:, "vimsyn_force_vim9", v:false) || "
" .. getline(1, 32)->join("
") =~# '
vim9s\%[cript]\>'

function s:has(feature)
return has(a:feature) || index(get(g:, "vimsyn_vim_features", []), a:feature) != -1