runtime(vim): Update base-syntax, fix function tail comments

Commit: 
https://github.com/vim/vim/commit/fc64ac0be2c4f9446798de4d66b029526d1afa85
Author: Doug Kearns <dougkea...@gmail.com>
Date:   Sat Jun 22 11:20:36 2024 +0200

    runtime(vim): Update base-syntax, fix function tail comments
    
    Match Vim9-script comments after :def and :enddef and legacy-script
    comments after :func and :endfunc, in any definition context.
    
    Highlight incorrect comment types after these commands as errors.
    
    fixes: #15062
    closes: #15072
    
    Signed-off-by: Doug Kearns <dougkea...@gmail.com>
    Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/runtime/syntax/generator/vim.vim.base 
b/runtime/syntax/generator/vim.vim.base
index adfd68ee6..6bb2d44c8 100644
--- a/runtime/syntax/generator/vim.vim.base
+++ b/runtime/syntax/generator/vim.vim.base
@@ -3,7 +3,7 @@
 " Maintainer:     Hirohito Higashi <h.east.727 ATMARK gmail.com>
 "         Doug Kearns <dougkea...@gmail.com>
 " URL:    https://github.com/vim-jp/syntax-vim-ex
-" Last Change:    2024 Jun 17
+" Last Change:    2024 Jun 21
 " Former Maintainer: Charles E. Campbell
 
 " DO NOT CHANGE DIRECTLY.
@@ -277,19 +277,19 @@ syn keyword       vimFuncKey      contained       
fu[nction]
 syn keyword    vimDefKey       contained       def
 syn keyword    vimMethodName   contained       empty len string
 
-syn region     vimFuncParams   contained       matchgroup=Delimiter start="(" 
skip=+
\s*\\|
\s*"\ + end=")" skipwhite skipnl 
nextgroup=vimFuncBody,vimFuncComment,vimEndfunction,vimFuncMod 
contains=vimFuncParam,@vimContinue
-syn region     vimDefParams    contained       matchgroup=Delimiter start="("  
           end=")" skipwhite skipnl 
nextgroup=vimDefBody,vimDefComment,vimEnddef,vimReturnType   
contains=vimDefParam,vim9Comment
+syn region     vimFuncParams   contained       matchgroup=Delimiter start="(" 
skip=+
\s*\\|
\s*"\ + end=")" skipwhite skipnl 
nextgroup=vimFuncBody,vimFuncComment,vimEndfunction,vimFuncMod,vim9CommentError 
       contains=vimFuncParam,@vimContinue
+syn region     vimDefParams    contained       matchgroup=Delimiter start="("  
           end=")" skipwhite skipnl 
nextgroup=vimDefBody,vimDefComment,vimEnddef,vimReturnType,vimCommentError  
contains=vimDefParam,vim9Comment
 syn match      vimFuncParam    contained       "\<\h\w*\>\|\.\.\."     
skipwhite nextgroup=vimFuncParamEquals
 syn match      vimDefParam     contained       "\<\h\w*\>"             
skipwhite nextgroup=vimParamType,vimFuncParamEquals
 
 syn match      vimFuncParamEquals contained    "="                     
skipwhite        nextgroup=@vimExprList
-syn match      vimFuncMod       contained      
"\<\%(abort\|closure\|dict\|range\)\>"  skipwhite skipnl 
nextgroup=vimFuncBody,vimFuncComment,vimEndfunction,vimFuncMod
+syn match      vimFuncMod       contained      
"\<\%(abort\|closure\|dict\|range\)\>"  skipwhite skipnl 
nextgroup=vimFuncBody,vimFuncComment,vimEndfunction,vimFuncMod,vim9CommentError
 
-syn region     vimFuncBody     contained       start="^"       
matchgroup=vimCommand end="\<endfu\%[nction]\>" contains=@vimFuncBodyList
-syn region     vimDefBody      contained       start="^"       
matchgroup=vimCommand end="\<enddef\>"  contains=@vimDefBodyList
+syn region     vimFuncBody     contained       start="^.\="    
matchgroup=vimCommand end="\<endfu\%[nction]\>" contains=@vimFuncBodyList 
skipwhite nextgroup=vimCmdSep,vimComment,vim9CommentError
+syn region     vimDefBody      contained       start="^.\="    
matchgroup=vimCommand end="\<enddef\>"  contains=@vimDefBodyList  skipwhite 
nextgroup=vimCmdSep,vim9Comment,vimCommentError
 
-syn match      vimEndfunction  "\<endf\%[unction]\>"
-syn match      vimEnddef       "\<enddef\>"
+syn match      vimEndfunction  "\<endf\%[unction]\>" skipwhite 
nextgroup=vimCmdSep,vimComment,vim9CommentError
+syn match      vimEnddef       "\<enddef\>"        skipwhite 
nextgroup=vimCmdSep,vim9Comment,vimCommentError
 
 if exists("g:vimsyn_folding") && g:vimsyn_folding =~# 'f'
  syn region    vimFuncFold     
start="^\s*:\=\s*fu\%[nction]\>!\=\s*\%(<[sS][iI][dD]>\|[sg]:\)\=\%(\i\|[#.]\|{.\{-1,}}\)\+\s*("
        end="^\s*:\=\s*endf\%[unction]\>" contains=vimFunction fold keepend 
extend transparent
@@ -303,7 +303,7 @@ syn match   vimFuncBlank contained  "\s\+"
 " Types: {{{2
 " =====
 " vimTypes : new for vim9
-syn region     vimReturnType   contained       start=":\s" end="$" 
matchgroup=vim9Comment end="\ze#" skipwhite skipnl 
nextgroup=vimDefBody,vimDefComment,vimEnddef contains=vimTypeSep transparent
+syn region     vimReturnType   contained       start=":\s" end="$" 
matchgroup=vim9Comment end="\ze[#"]" skipwhite skipnl 
nextgroup=vimDefBody,vimDefComment,vimEnddef,vimCommentError 
contains=vimTypeSep transparent
 syn match      vimParamType    contained       ":\s\+ "                        
skipwhite skipnl nextgroup=vimFuncParamEquals                   
contains=vimTypeSep,@vimType
 
 syn match      vimTypeSep      contained       ":\s\@=" skipwhite 
nextgroup=@vimType
@@ -408,6 +408,9 @@ else
   syn cluster vimComment contains=vimComment
 endif
 
+syn match      vim9CommentError        contained       "#.*"
+syn match      vimCommentError contained       +".*+
+
 " Environment Variables: {{{2
 " =====================
 syn match      vimEnvvar       "\$\I\i*"
@@ -1091,7 +1094,9 @@ if !exists("skip_vim_syntax_inits")
  hi def link vimCmplxRepeat    SpecialChar
  hi def link vimCommand        Statement
  hi def link vimComment        Comment
+ hi def link vimCommentError   vimError
  hi def link vim9Comment       Comment
+ hi def link vim9CommentError  vimError
  hi def link vimCommentString  vimString
  hi def link vimCommentTitle   PreProc
  hi def link vim9CommentTitle  PreProc
@@ -1100,7 +1105,7 @@ if !exists("skip_vim_syntax_inits")
  hi def link vimContinue       Special
  hi def link vimContinueComment        vimComment
  hi def link vimCtrlChar       SpecialChar
- hi def link vimDefComment     vimComment
+ hi def link vimDefComment     vim9Comment
  hi def link vimDefKey vimCommand
  hi def link vimDefParam vimVar
  hi def link vimEcho   vimCommand
diff --git 
a/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comment_errors_00.dump 
b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comment_errors_00.dump
new file mode 100644
index 000000000..04f643ddf
--- /dev/null
+++ 
b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comment_errors_00.dump
@@ -0,0 +1,20 @@
+>v+0#af5f00255#ffffff0|i|m|9|s|c|r|i|p|t| +0#0000000&@64
+@75
+|#+0#0000e05&| |V|i|m|9| |:|f|u|n|c|t|i|o|n| |a|n|d| |:|d|e|f| |t|a|i|l| 
|c|o|m@1|e|n|t| |e|r@1|o|r|s| +0#0000000&@29
+|#+0#0000e05&| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |u|n|l|e|t|!| 
|g|:|v|i|m|s|y|n|_|f|o|l|d|i|n|g| +0#0000000&@34
+@75
+|f+0#af5f00255&|u|n| +0#0000000&|T|e|s|t|1|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@14|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|1+0#e000002&| +0#0000000&@64
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|#+0#ffffff16#ff404010| |e|n|d|f|u|n| 
+0#0000000#ffffff0@34
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|T|e|s|t|2|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@12|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|2+0#e000002&| +0#0000000&@64
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|"+0#ffffff16#ff404010| |e|n|d@1|e|f| 
+0#0000000#ffffff0@34
+@75
+|f+0#af5f00255&|u|n| +0#0000000&|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@14|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@2|f+0#af5f00255&|u|n| 
+0#0000000&|s+0#e000e06&|:|D+0#0000000&|o|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@8|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|3+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|#+0#ffffff16#ff404010| 
|e|n|d|f|u|n| +0#0000000#ffffff0@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&@54
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|#+0#ffffff16#ff404010| |e|n|d|f|u|n| 
+0#0000000#ffffff0@34
+@57|1|,|1| @10|T|o|p| 
diff --git 
a/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comment_errors_01.dump 
b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comment_errors_01.dump
new file mode 100644
index 000000000..cb7caf568
--- /dev/null
+++ 
b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comment_errors_01.dump
@@ -0,0 +1,20 @@
+|f+0#af5f00255#ffffff0|u|n| +0#0000000&|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@14|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@2|f+0#af5f00255&|u|n| 
+0#0000000&|s+0#e000e06&|:|D+0#0000000&|o|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@8|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|3+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|#+0#ffffff16#ff404010| 
|e|n|d|f|u|n| +0#0000000#ffffff0@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&@54
+>e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|#+0#ffffff16#ff404010| |e|n|d|f|u|n| 
+0#0000000#ffffff0@34
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|T|e|s|t|4|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@12|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@2|d+0#af5f00255&|e|f| +0#0000000&|D|o|T|e|s|t|4|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@8|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|4+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@23|"+0#ffffff16#ff404010| 
|e|n|d@1|e|f| +0#0000000#ffffff0@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|D|o|T|e|s|t|4|(+0#e000e06&|)| 
+0#0000000&@56
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|"+0#ffffff16#ff404010| |e|n|d@1|e|f| 
+0#0000000#ffffff0@34
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|T|e|s|t|5|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@12|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@2|f+0#af5f00255&|u|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@10|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|5+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|#+0#ffffff16#ff404010| 
|e|n|d|f|u|n| +0#0000000#ffffff0@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&@56
+@57|1|9|,|1| @9|5|2|%| 
diff --git 
a/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comment_errors_02.dump 
b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comment_errors_02.dump
new file mode 100644
index 000000000..e74df6743
--- /dev/null
+++ 
b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comment_errors_02.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@1|r+0#af5f00255&|e|t|u|r|n| 
+0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| +0#0000000&@56
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|"+0#ffffff16#ff404010| |e|n|d@1|e|f| 
+0#0000000#ffffff0@34
+@75
+|f+0#af5f00255&|u|n| +0#0000000&|T|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@14|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@2|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|D+0#0000000&|o|T|e|s|t|6|(+0#e000e06&|)|:+0#0000000&|
 |n+0#00e0003&|u|m|b|e|r| +0#0000000&@6|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@4>r+0#af5f00255&|e|t|u|r|n| +0#0000000&|6+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@23|"+0#ffffff16#ff404010| 
|e|n|d@1|e|f| +0#0000000#ffffff0@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&@54
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|#+0#ffffff16#ff404010| |e|n|d|f|u|n| 
+0#0000000#ffffff0@34
+@75
+|f+0#af5f00255&|o|r| +0#0000000&|d+0#00e0e07&| +0#0000000&|i+0#af5f00255&|n| 
+0#0000000&|r+0#00e0e07&|a|n|g|e|(+0#e000e06&|1+0#e000002&|,+0#0000000&| 
|6+0#e000002&|)+0#e000e06&| +0#0000000&@54
+@2|e+0#af5f00255&|x|e|c| +0#0000000&|$+0#e000002&|'|e|c|h|o| 
|T|e|s|t|{+0#e000e06&|d+0#00e0e07&|}+0#e000e06&|(+0#e000002&|)|'| +0#0000000&@50
+|e+0#af5f00255&|n|d|f|o|r| +0#0000000&@68
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|3|7|,|5| @9|B|o|t| 
diff --git 
a/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comment_errors_99.dump 
b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comment_errors_99.dump
new file mode 100644
index 000000000..3e5b28007
--- /dev/null
+++ 
b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comment_errors_99.dump
@@ -0,0 +1,20 @@
+|e+0#af5f00255#ffffff0|n|d@1|e|f| +0#0000000&@25|"+0#ffffff16#ff404010| 
|e|n|d@1|e|f| +0#0000000#ffffff0@34
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|T|e|s|t|5|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@12|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@2|f+0#af5f00255&|u|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@10|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|5+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|#+0#ffffff16#ff404010| 
|e|n|d|f|u|n| +0#0000000#ffffff0@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&@56
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|"+0#ffffff16#ff404010| |e|n|d@1|e|f| 
+0#0000000#ffffff0@34
+@75
+|f+0#af5f00255&|u|n| +0#0000000&|T|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@14|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@2|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|D+0#0000000&|o|T|e|s|t|6|(+0#e000e06&|)|:+0#0000000&|
 |n+0#00e0003&|u|m|b|e|r| +0#0000000&@6|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|6+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@23|"+0#ffffff16#ff404010| 
|e|n|d@1|e|f| +0#0000000#ffffff0@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&@54
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|#+0#ffffff16#ff404010| |e|n|d|f|u|n| 
+0#0000000#ffffff0@34
+@75
+|f+0#af5f00255&|o|r| +0#0000000&|d+0#00e0e07&| +0#0000000&|i+0#af5f00255&|n| 
+0#0000000&|r+0#00e0e07&|a|n|g|e|(+0#e000e06&|1+0#e000002&|,+0#0000000&| 
|6+0#e000002&|)+0#e000e06&| +0#0000000&@54
+@2|e+0#af5f00255&|x|e|c| +0#0000000&|$+0#e000002&|'|e|c|h|o| 
|T|e|s|t|{+0#e000e06&|d+0#00e0e07&|}+0#e000e06&|(+0#e000002&|)|'| +0#0000000&@50
+>e+0#af5f00255&|n|d|f|o|r| +0#0000000&@68
+@57|4@1|,|1| @9|B|o|t| 
diff --git 
a/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comments_00.dump 
b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comments_00.dump
new file mode 100644
index 000000000..b6ed4904d
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comments_00.dump
@@ -0,0 +1,20 @@
+>v+0#af5f00255#ffffff0|i|m|9|s|c|r|i|p|t| +0#0000000&@64
+@75
+|#+0#0000e05&| |V|i|m|9| |:|f|u|n|c|t|i|o|n| |a|n|d| |:|d|e|f| |t|a|i|l| 
|c|o|m@1|e|n|t|s| +0#0000000&@35
+|#+0#0000e05&| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |u|n|l|e|t|!| 
|g|:|v|i|m|s|y|n|_|f|o|l|d|i|n|g| +0#0000000&@34
+@75
+|f+0#af5f00255&|u|n| +0#0000000&|T|e|s|t|1|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@14|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|1+0#e000002&| +0#0000000&@64
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|T|e|s|t|2|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@12|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|2+0#e000002&| +0#0000000&@64
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@75
+|f+0#af5f00255&|u|n| +0#0000000&|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@14|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@2|f+0#af5f00255&|u|n| 
+0#0000000&|s+0#e000e06&|:|D+0#0000000&|o|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@8|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|3+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&@54
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@57|1|,|1| @10|T|o|p| 
diff --git 
a/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comments_01.dump 
b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comments_01.dump
new file mode 100644
index 000000000..6cb37d125
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comments_01.dump
@@ -0,0 +1,20 @@
+|f+0#af5f00255#ffffff0|u|n| +0#0000000&|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@14|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@2|f+0#af5f00255&|u|n| 
+0#0000000&|s+0#e000e06&|:|D+0#0000000&|o|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@8|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|3+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&@54
+>e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|T|e|s|t|4|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@12|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@2|d+0#af5f00255&|e|f| +0#0000000&|D|o|T|e|s|t|4|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@8|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|4+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@23|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|D|o|T|e|s|t|4|(+0#e000e06&|)| 
+0#0000000&@56
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|T|e|s|t|5|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@12|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@2|f+0#af5f00255&|u|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@10|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|5+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&@56
+@57|1|9|,|1| @9|5|2|%| 
diff --git 
a/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comments_02.dump 
b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comments_02.dump
new file mode 100644
index 000000000..7df9e8f15
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comments_02.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@1|r+0#af5f00255&|e|t|u|r|n| 
+0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| +0#0000000&@56
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@75
+|f+0#af5f00255&|u|n| +0#0000000&|T|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@14|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@2|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|D+0#0000000&|o|T|e|s|t|6|(+0#e000e06&|)|:+0#0000000&|
 |n+0#00e0003&|u|m|b|e|r| +0#0000000&@6|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@4>r+0#af5f00255&|e|t|u|r|n| +0#0000000&|6+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@23|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&@54
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@75
+|f+0#af5f00255&|o|r| +0#0000000&|d+0#00e0e07&| +0#0000000&|i+0#af5f00255&|n| 
+0#0000000&|r+0#00e0e07&|a|n|g|e|(+0#e000e06&|1+0#e000002&|,+0#0000000&| 
|6+0#e000002&|)+0#e000e06&| +0#0000000&@54
+@2|e+0#af5f00255&|x|e|c| +0#0000000&|$+0#e000002&|'|e|c|h|o| 
|T|e|s|t|{+0#e000e06&|d+0#00e0e07&|}+0#e000e06&|(+0#e000002&|)|'| +0#0000000&@50
+|e+0#af5f00255&|n|d|f|o|r| +0#0000000&@68
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|3|7|,|5| @9|B|o|t| 
diff --git 
a/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comments_99.dump 
b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comments_99.dump
new file mode 100644
index 000000000..42d9f8cdc
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim9_ex_function_def_tail_comments_99.dump
@@ -0,0 +1,20 @@
+|e+0#af5f00255#ffffff0|n|d@1|e|f| +0#0000000&@25|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|T|e|s|t|5|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@12|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@2|f+0#af5f00255&|u|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@10|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|5+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&@56
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@75
+|f+0#af5f00255&|u|n| +0#0000000&|T|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@14|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@2|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|D+0#0000000&|o|T|e|s|t|6|(+0#e000e06&|)|:+0#0000000&|
 |n+0#00e0003&|u|m|b|e|r| +0#0000000&@6|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|6+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@23|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&@54
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@75
+|f+0#af5f00255&|o|r| +0#0000000&|d+0#00e0e07&| +0#0000000&|i+0#af5f00255&|n| 
+0#0000000&|r+0#00e0e07&|a|n|g|e|(+0#e000e06&|1+0#e000002&|,+0#0000000&| 
|6+0#e000002&|)+0#e000e06&| +0#0000000&@54
+@2|e+0#af5f00255&|x|e|c| +0#0000000&|$+0#e000002&|'|e|c|h|o| 
|T|e|s|t|{+0#e000e06&|d+0#00e0e07&|}+0#e000e06&|(+0#e000002&|)|'| +0#0000000&@50
+>e+0#af5f00255&|n|d|f|o|r| +0#0000000&@68
+@57|4@1|,|1| @9|B|o|t| 
diff --git a/runtime/syntax/testdir/dumps/vim_ex_def_05.dump 
b/runtime/syntax/testdir/dumps/vim_ex_def_05.dump
index 2db207b43..076428cd9 100644
--- a/runtime/syntax/testdir/dumps/vim_ex_def_05.dump
+++ b/runtime/syntax/testdir/dumps/vim_ex_def_05.dump
@@ -1,6 +1,6 @@
 | +0&#ffffff0@74
 |d+0#af5f00255&|e|f| +0#0000000&|F|o@1|(+0#e000e06&|)| +0#0000000&@65
-|e+0#af5f00255&|n|d@1|e|f| +0#0000000&|"+0#0000e05&| |c|o|m@1|e|n|t| 
+0#0000000&@58
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&|#+0#0000e05&| |c|o|m@1|e|n|t| 
+0#0000000&@58
 @75
 @75
 >"+0#0000e05&| |p|a|r|a|m|e|t|e|r|s| +0#0000000&@62
diff --git 
a/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comment_errors_00.dump 
b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comment_errors_00.dump
new file mode 100644
index 000000000..04f6fd216
--- /dev/null
+++ 
b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comment_errors_00.dump
@@ -0,0 +1,20 @@
+>"+0#0000e05#ffffff0| |V|i|m| |:|f|u|n|c|t|i|o|n| |a|n|d| |:|d|e|f| |t|a|i|l| 
|c|o|m@1|e|n|t| |e|r@1|o|r|s| +0#0000000&@30
+|"+0#0000e05&| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |u|n|l|e|t|!| 
|g|:|v|i|m|s|y|n|_|f|o|l|d|i|n|g| +0#0000000&@34
+@75
+|f+0#af5f00255&|u|n| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|1|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@12|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|1+0#e000002&| +0#0000000&@64
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|#+0#ffffff16#ff404010| |e|n|d|f|u|n| 
+0#0000000#ffffff0@34
+@75
+|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|2|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@10|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|2+0#e000002&| +0#0000000&@64
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|"+0#ffffff16#ff404010| |e|n|d@1|e|f| 
+0#0000000#ffffff0@34
+@75
+|f+0#af5f00255&|u|n| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@12|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@2|f+0#af5f00255&|u|n| 
+0#0000000&|s+0#e000e06&|:|D+0#0000000&|o|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@8|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|3+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|#+0#ffffff16#ff404010| 
|e|n|d|f|u|n| +0#0000000#ffffff0@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&@54
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|#+0#ffffff16#ff404010| |e|n|d|f|u|n| 
+0#0000000#ffffff0@34
+@75
+|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|4|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@10|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@57|1|,|1| @10|T|o|p| 
diff --git 
a/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comment_errors_01.dump 
b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comment_errors_01.dump
new file mode 100644
index 000000000..3e5b4bd02
--- /dev/null
+++ 
b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comment_errors_01.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@3|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|3+0#e000002&| 
+0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|#+0#ffffff16#ff404010| 
|e|n|d|f|u|n| +0#0000000#ffffff0@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&@54
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|#+0#ffffff16#ff404010| |e|n|d|f|u|n| 
+0#0000000#ffffff0@34
+@75
+>d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|4|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@10|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@2|d+0#af5f00255&|e|f| +0#0000000&|D|o|T|e|s|t|4|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@8|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|4+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@23|"+0#ffffff16#ff404010| 
|e|n|d@1|e|f| +0#0000000#ffffff0@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|D|o|T|e|s|t|4|(+0#e000e06&|)| 
+0#0000000&@56
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|"+0#ffffff16#ff404010| |e|n|d@1|e|f| 
+0#0000000#ffffff0@34
+@75
+|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|5|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@10|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@2|f+0#af5f00255&|u|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@10|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|5+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|#+0#ffffff16#ff404010| 
|e|n|d|f|u|n| +0#0000000#ffffff0@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&@56
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|"+0#ffffff16#ff404010| |e|n|d@1|e|f| 
+0#0000000#ffffff0@34
+@75
+@57|1|9|,|1| @9|5|4|%| 
diff --git 
a/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comment_errors_02.dump 
b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comment_errors_02.dump
new file mode 100644
index 000000000..0d9de4b14
--- /dev/null
+++ 
b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comment_errors_02.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@74
+|f+0#af5f00255&|u|n| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@12|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@2|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|D+0#0000000&|o|T|e|s|t|6|(+0#e000e06&|)|:+0#0000000&|
 |n+0#00e0003&|u|m|b|e|r| +0#0000000&@6|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|6+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@23|"+0#ffffff16#ff404010| 
|e|n|d@1|e|f| +0#0000000#ffffff0@34
+@2>r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&@54
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|#+0#ffffff16#ff404010| |e|n|d|f|u|n| 
+0#0000000#ffffff0@34
+@75
+|f+0#af5f00255&|o|r| +0#0000000&|d+0#00e0e07&| +0#0000000&|i+0#af5f00255&|n| 
+0#0000000&|r+0#00e0e07&|a|n|g|e|(+0#e000e06&|1+0#e000002&|,+0#0000000&| 
|6+0#e000002&|)+0#e000e06&|-+0#af5f00255&|>|r+0#00e0e07&|e|v|e|r|s|e|(+0#e000e06&|)|
 +0#0000000&@43
+@2|e+0#af5f00255&|x|e|c| +0#0000000&|$+0#e000002&|'|e|c|h|o| 
|s|:|T|e|s|t|{+0#e000e06&|d+0#00e0e07&|}+0#e000e06&|(+0#e000002&|)|'| 
+0#0000000&@48
+@2|e+0#af5f00255&|x|e|c| +0#0000000&|$+0#e000002&|'|d|e|l|f|u|n|c|t|i|o|n| 
|s|:|T|e|s|t|{+0#e000e06&|d+0#00e0e07&|}+0#e000e06&|'+0#e000002&| +0#0000000&@43
+|e+0#af5f00255&|n|d|f|o|r| +0#0000000&@68
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|3|7|,|3| @9|B|o|t| 
diff --git 
a/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comment_errors_99.dump 
b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comment_errors_99.dump
new file mode 100644
index 000000000..ac4a64b8d
--- /dev/null
+++ 
b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comment_errors_99.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@74
+|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|5|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@10|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@2|f+0#af5f00255&|u|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@10|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|5+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|#+0#ffffff16#ff404010| 
|e|n|d|f|u|n| +0#0000000#ffffff0@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&@56
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|"+0#ffffff16#ff404010| |e|n|d@1|e|f| 
+0#0000000#ffffff0@34
+@75
+|f+0#af5f00255&|u|n| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@12|#+0#ffffff16#ff404010| |f|u|n| 
+0#0000000#ffffff0@37
+@2|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|D+0#0000000&|o|T|e|s|t|6|(+0#e000e06&|)|:+0#0000000&|
 |n+0#00e0003&|u|m|b|e|r| +0#0000000&@6|"+0#ffffff16#ff404010| |d|e|f| 
+0#0000000#ffffff0@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|6+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@23|"+0#ffffff16#ff404010| 
|e|n|d@1|e|f| +0#0000000#ffffff0@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&@54
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|#+0#ffffff16#ff404010| |e|n|d|f|u|n| 
+0#0000000#ffffff0@34
+@75
+|f+0#af5f00255&|o|r| +0#0000000&|d+0#00e0e07&| +0#0000000&|i+0#af5f00255&|n| 
+0#0000000&|r+0#00e0e07&|a|n|g|e|(+0#e000e06&|1+0#e000002&|,+0#0000000&| 
|6+0#e000002&|)+0#e000e06&|-+0#af5f00255&|>|r+0#00e0e07&|e|v|e|r|s|e|(+0#e000e06&|)|
 +0#0000000&@43
+@2|e+0#af5f00255&|x|e|c| +0#0000000&|$+0#e000002&|'|e|c|h|o| 
|s|:|T|e|s|t|{+0#e000e06&|d+0#00e0e07&|}+0#e000e06&|(+0#e000002&|)|'| 
+0#0000000&@48
+@2|e+0#af5f00255&|x|e|c| +0#0000000&|$+0#e000002&|'|d|e|l|f|u|n|c|t|i|o|n| 
|s|:|T|e|s|t|{+0#e000e06&|d+0#00e0e07&|}+0#e000e06&|'+0#e000002&| +0#0000000&@43
+>e+0#af5f00255&|n|d|f|o|r| +0#0000000&@68
+@57|4|3|,|1| @9|B|o|t| 
diff --git 
a/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comments_00.dump 
b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comments_00.dump
new file mode 100644
index 000000000..f8c0ccc90
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comments_00.dump
@@ -0,0 +1,20 @@
+>"+0#0000e05#ffffff0| |V|i|m| |:|f|u|n|c|t|i|o|n| |a|n|d| |:|d|e|f| |t|a|i|l| 
|c|o|m@1|e|n|t|s| +0#0000000&@36
+|"+0#0000e05&| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |u|n|l|e|t|!| 
|g|:|v|i|m|s|y|n|_|f|o|l|d|i|n|g| +0#0000000&@34
+@75
+|f+0#af5f00255&|u|n| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|1|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@12|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|1+0#e000002&| +0#0000000&@64
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@75
+|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|2|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@10|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|2+0#e000002&| +0#0000000&@64
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@75
+|f+0#af5f00255&|u|n| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@12|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@2|f+0#af5f00255&|u|n| 
+0#0000000&|s+0#e000e06&|:|D+0#0000000&|o|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@8|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|3+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&@54
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@75
+|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|4|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@10|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@57|1|,|1| @10|T|o|p| 
diff --git 
a/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comments_01.dump 
b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comments_01.dump
new file mode 100644
index 000000000..326a2496d
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comments_01.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@3|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|3+0#e000002&| 
+0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|3|(+0#e000e06&|)| 
+0#0000000&@54
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@75
+>d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|4|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@10|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@2|d+0#af5f00255&|e|f| +0#0000000&|D|o|T|e|s|t|4|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@8|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|4+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@23|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|D|o|T|e|s|t|4|(+0#e000e06&|)| 
+0#0000000&@56
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@75
+|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|5|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@10|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@2|f+0#af5f00255&|u|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@10|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|5+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&@56
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@75
+@57|1|9|,|1| @9|5|4|%| 
diff --git 
a/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comments_02.dump 
b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comments_02.dump
new file mode 100644
index 000000000..8dcb0b979
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comments_02.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@74
+|f+0#af5f00255&|u|n| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@12|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@2|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|D+0#0000000&|o|T|e|s|t|6|(+0#e000e06&|)|:+0#0000000&|
 |n+0#00e0003&|u|m|b|e|r| +0#0000000&@6|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|6+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@23|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@2>r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&@54
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@75
+|f+0#af5f00255&|o|r| +0#0000000&|d+0#00e0e07&| +0#0000000&|i+0#af5f00255&|n| 
+0#0000000&|r+0#00e0e07&|a|n|g|e|(+0#e000e06&|1+0#e000002&|,+0#0000000&| 
|6+0#e000002&|)+0#e000e06&|-+0#af5f00255&|>|r+0#00e0e07&|e|v|e|r|s|e|(+0#e000e06&|)|
 +0#0000000&@43
+@2|e+0#af5f00255&|x|e|c| +0#0000000&|$+0#e000002&|'|e|c|h|o| 
|s|:|T|e|s|t|{+0#e000e06&|d+0#00e0e07&|}+0#e000e06&|(+0#e000002&|)|'| 
+0#0000000&@48
+@2|e+0#af5f00255&|x|e|c| +0#0000000&|$+0#e000002&|'|d|e|l|f|u|n|c|t|i|o|n| 
|s|:|T|e|s|t|{+0#e000e06&|d+0#00e0e07&|}+0#e000e06&|'+0#e000002&| +0#0000000&@43
+|e+0#af5f00255&|n|d|f|o|r| +0#0000000&@68
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|3|7|,|3| @9|B|o|t| 
diff --git 
a/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comments_99.dump 
b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comments_99.dump
new file mode 100644
index 000000000..02e15091b
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim_ex_function_def_tail_comments_99.dump
@@ -0,0 +1,20 @@
+| +0&#ffffff0@74
+|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|5|(+0#e000e06&|)|:+0#0000000&| 
|n+0#00e0003&|u|m|b|e|r| +0#0000000&@10|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@2|f+0#af5f00255&|u|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@10|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|5+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@23|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|D|o|T|e|s|t|5|(+0#e000e06&|)| 
+0#0000000&@56
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@25|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@75
+|f+0#af5f00255&|u|n| 
+0#0000000&|s+0#e000e06&|:|T+0#0000000&|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&|a+0#e000e06&|b|o|r|t| +0#0000000&@12|"+0#0000e05&| |f|u|n| 
+0#0000000&@37
+@2|d+0#af5f00255&|e|f| 
+0#0000000&|s+0#e000e06&|:|D+0#0000000&|o|T|e|s|t|6|(+0#e000e06&|)|:+0#0000000&|
 |n+0#00e0003&|u|m|b|e|r| +0#0000000&@6|#+0#0000e05&| |d|e|f| +0#0000000&@37
+@4|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|6+0#e000002&| +0#0000000&@62
+@2|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@23|#+0#0000e05&| |e|n|d@1|e|f| 
+0#0000000&@34
+@2|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|s|:|D|o|T|e|s|t|6|(+0#e000e06&|)| 
+0#0000000&@54
+|e+0#af5f00255&|n|d|f|u|n| +0#0000000&@25|"+0#0000e05&| |e|n|d|f|u|n| 
+0#0000000&@34
+@75
+|f+0#af5f00255&|o|r| +0#0000000&|d+0#00e0e07&| +0#0000000&|i+0#af5f00255&|n| 
+0#0000000&|r+0#00e0e07&|a|n|g|e|(+0#e000e06&|1+0#e000002&|,+0#0000000&| 
|6+0#e000002&|)+0#e000e06&|-+0#af5f00255&|>|r+0#00e0e07&|e|v|e|r|s|e|(+0#e000e06&|)|
 +0#0000000&@43
+@2|e+0#af5f00255&|x|e|c| +0#0000000&|$+0#e000002&|'|e|c|h|o| 
|s|:|T|e|s|t|{+0#e000e06&|d+0#00e0e07&|}+0#e000e06&|(+0#e000002&|)|'| 
+0#0000000&@48
+@2|e+0#af5f00255&|x|e|c| +0#0000000&|$+0#e000002&|'|d|e|l|f|u|n|c|t|i|o|n| 
|s|:|T|e|s|t|{+0#e000e06&|d+0#00e0e07&|}+0#e000e06&|'+0#e000002&| +0#0000000&@43
+>e+0#af5f00255&|n|d|f|o|r| +0#0000000&@68
+@57|4|3|,|1| @9|B|o|t| 
diff --git 
a/runtime/syntax/testdir/input/vim9_ex_function_def_tail_comment_errors.vim 
b/runtime/syntax/testdir/input/vim9_ex_function_def_tail_comment_errors.vim
new file mode 100644
index 000000000..b4b9f6de0
--- /dev/null
+++ b/runtime/syntax/testdir/input/vim9_ex_function_def_tail_comment_errors.vim
@@ -0,0 +1,44 @@
+vim9script
+
+# Vim9 :function and :def tail comment errors
+# VIM_TEST_SETUP unlet! g:vimsyn_folding
+
+fun Test1() abort              # fun
+  return 1
+endfun                         # endfun
+
+def Test2(): number            " def
+  return 2
+enddef                         " enddef
+
+fun Test3() abort              # fun
+  fun s:DoTest3() abort                # fun
+    return 3
+  endfun                       # endfun
+  return s:DoTest3()
+endfun                         # endfun
+
+def Test4(): number            " def
+  def DoTest4(): number                " def
+    return 4
+  enddef                       " enddef
+  return DoTest4()
+enddef                         " enddef
+
+def Test5(): number            " def
+  fun DoTest5() abort          # fun
+    return 5
+  endfun                       # endfun
+  return DoTest5()
+enddef                         " enddef
+
+fun Test6() abort              # fun
+  def s:DoTest6(): number      " def
+    return 6
+  enddef                       " enddef
+  return s:DoTest6()
+endfun                         # endfun
+
+for d in range(1, 6)
+  exec $'echo Test{d}()'
+endfor
diff --git 
a/runtime/syntax/testdir/input/vim9_ex_function_def_tail_comments.vim 
b/runtime/syntax/testdir/input/vim9_ex_function_def_tail_comments.vim
new file mode 100644
index 000000000..12f7942cf
--- /dev/null
+++ b/runtime/syntax/testdir/input/vim9_ex_function_def_tail_comments.vim
@@ -0,0 +1,44 @@
+vim9script
+
+# Vim9 :function and :def tail comments
+# VIM_TEST_SETUP unlet! g:vimsyn_folding
+
+fun Test1() abort              " fun
+  return 1
+endfun                         " endfun
+
+def Test2(): number            # def
+  return 2
+enddef                         # enddef
+
+fun Test3() abort              " fun
+  fun s:DoTest3() abort                " fun
+    return 3
+  endfun                       " endfun
+  return s:DoTest3()
+endfun                         " endfun
+
+def Test4(): number            # def
+  def DoTest4(): number                # def
+    return 4
+  enddef                       # enddef
+  return DoTest4()
+enddef                         # enddef
+
+def Test5(): number            # def
+  fun DoTest5() abort          " fun
+    return 5
+  endfun                       " endfun
+  return DoTest5()
+enddef                         # enddef
+
+fun Test6() abort              " fun
+  def s:DoTest6(): number      # def
+    return 6
+  enddef                       # enddef
+  return s:DoTest6()
+endfun                         " endfun
+
+for d in range(1, 6)
+  exec $'echo Test{d}()'
+endfor
diff --git a/runtime/syntax/testdir/input/vim_ex_def.vim 
b/runtime/syntax/testdir/input/vim_ex_def.vim
index 2685ba5fd..a1d538158 100644
--- a/runtime/syntax/testdir/input/vim_ex_def.vim
+++ b/runtime/syntax/testdir/input/vim_ex_def.vim
@@ -85,7 +85,7 @@ def Foo()
 enddef | echo "Foo"
 
 def Foo()
-enddef " comment
+enddef # comment
 
 
 " parameters
diff --git a/runtime/syntax/testdir/input/vim_ex_def_fold.vim 
b/runtime/syntax/testdir/input/vim_ex_def_fold.vim
index 3326075a3..d85f27352 100644
--- a/runtime/syntax/testdir/input/vim_ex_def_fold.vim
+++ b/runtime/syntax/testdir/input/vim_ex_def_fold.vim
@@ -86,7 +86,7 @@ def Foo()
 enddef | echo "Foo"
 
 def Foo()
-enddef " comment
+enddef # comment
 
 
 " parameters
diff --git 
a/runtime/syntax/testdir/input/vim_ex_function_def_tail_comment_errors.vim 
b/runtime/syntax/testdir/input/vim_ex_function_def_tail_comment_errors.vim
new file mode 100644
index 000000000..e5d746439
--- /dev/null
+++ b/runtime/syntax/testdir/input/vim_ex_function_def_tail_comment_errors.vim
@@ -0,0 +1,43 @@
+" Vim :function and :def tail comment errors
+" VIM_TEST_SETUP unlet! g:vimsyn_folding
+
+fun s:Test1() abort            # fun
+  return 1
+endfun                         # endfun
+
+def s:Test2(): number          " def
+  return 2
+enddef                         " enddef
+
+fun s:Test3() abort            # fun
+  fun s:DoTest3() abort                # fun
+    return 3
+  endfun                       # endfun
+  return s:DoTest3() 
+endfun                         # endfun
+
+def s:Test4(): number          " def
+  def DoTest4(): number                " def
+    return 4
+  enddef                       " enddef
+  return DoTest4()
+enddef                         " enddef
+
+def s:Test5(): number          " def
+  fun DoTest5() abort          # fun
+    return 5
+  endfun                       # endfun
+  return DoTest5()
+enddef                         " enddef
+
+fun s:Test6() abort            # fun
+  def s:DoTest6(): number      " def
+    return 6
+  enddef                       " enddef
+  return s:DoTest6()
+endfun                         # endfun
+
+for d in range(1, 6)->reverse()
+  exec $'echo s:Test{d}()'
+  exec $'delfunction s:Test{d}'
+endfor
diff --git a/runtime/syntax/testdir/input/vim_ex_function_def_tail_comments.vim 
b/runtime/syntax/testdir/input/vim_ex_function_def_tail_comments.vim
new file mode 100644
index 000000000..e46bf752e
--- /dev/null
+++ b/runtime/syntax/testdir/input/vim_ex_function_def_tail_comments.vim
@@ -0,0 +1,43 @@
+" Vim :function and :def tail comments
+" VIM_TEST_SETUP unlet! g:vimsyn_folding
+
+fun s:Test1() abort            " fun
+  return 1
+endfun                         " endfun
+
+def s:Test2(): number          # def
+  return 2
+enddef                         # enddef
+
+fun s:Test3() abort            " fun
+  fun s:DoTest3() abort                " fun
+    return 3
+  endfun                       " endfun
+  return s:DoTest3() 
+endfun                         " endfun
+
+def s:Test4(): number          # def
+  def DoTest4(): number                # def
+    return 4
+  enddef                       # enddef
+  return DoTest4()
+enddef                         # enddef
+
+def s:Test5(): number          # def
+  fun DoTest5() abort          " fun
+    return 5
+  endfun                       " endfun
+  return DoTest5()
+enddef                         # enddef
+
+fun s:Test6() abort            " fun
+  def s:DoTest6(): number      # def
+    return 6
+  enddef                       # enddef
+  return s:DoTest6()
+endfun                         " endfun
+
+for d in range(1, 6)->reverse()
+  exec $'echo s:Test{d}()'
+  exec $'delfunction s:Test{d}'
+endfor
diff --git a/runtime/syntax/vim.vim b/runtime/syntax/vim.vim
index 033251f63..ca23000d9 100644
--- a/runtime/syntax/vim.vim
+++ b/runtime/syntax/vim.vim
@@ -3,7 +3,7 @@
 " Maintainer:     Hirohito Higashi <h.east.727 ATMARK gmail.com>
 "         Doug Kearns <dougkea...@gmail.com>
 " URL:    https://github.com/vim-jp/syntax-vim-ex
-" Last Change:    2024 Jun 15
+" Last Change:    2024 Jun 21
 " Former Maintainer: Charles E. Campbell
 
 " DO NOT CHANGE DIRECTLY.
@@ -108,11 +108,11 @@ syn keyword vimFuncName contained abs acos add and append 
appendbufline argc arg
 syn keyword vimFuncName contained clearmatches col complete complete_add 
complete_check complete_info confirm copy cos cosh count cscope_connection 
cursor debugbreak deepcopy delete deletebufline did_filetype diff diff_filler 
diff_hlID digraph_get digraph_getlist digraph_set digraph_setlist echoraw empty 
environ err_teapot escape eval eventhandler executable execute exepath exists 
exists_compiled exp expand expandcmd extend extendnew feedkeys filecopy 
filereadable filewritable filter finddir findfile flatten flattennew float2nr 
floor fmod fnameescape fnamemodify foldclosed foldclosedend foldlevel foldtext 
foldtextresult foreach foreground fullcommand funcref function garbagecollect 
get getbufinfo getbufline getbufoneline getbufvar getcellwidths getchangelist 
getchar
 syn keyword vimFuncName contained getcharmod getcharpos getcharsearch 
getcharstr getcmdcompltype getcmdline getcmdpos getcmdscreenpos getcmdtype 
getcmdwintype getcompletion getcurpos getcursorcharpos getcwd getenv 
getfontname getfperm getfsize getftime getftype getimstatus getjumplist getline 
getloclist getmarklist getmatches getmousepos getmouseshape getpid getpos 
getqflist getreg getreginfo getregion getregionpos getregtype getscriptinfo 
gettabinfo gettabvar gettabwinvar gettagstack gettext getwininfo getwinpos 
getwinposx getwinposy getwinvar glob glob2regpat globpath has has_key 
haslocaldir hasmapto histadd histdel histget histnr hlID hlexists hlget hlset 
hostname iconv indent index indexof input inputdialog inputlist inputrestore 
inputsave inputsecret insert
 syn keyword vimFuncName contained instanceof interrupt invert isabsolutepath 
isdirectory isinf islocked isnan items job_getchannel job_info job_setoptions 
job_start job_status job_stop join js_decode js_encode json_decode json_encode 
keys keytrans len libcall libcallnr line line2byte lispindent list2blob 
list2str listener_add listener_flush listener_remove localtime log log10 
luaeval map maparg mapcheck maplist mapnew mapset match matchadd matchaddpos 
matcharg matchbufline matchdelete matchend matchfuzzy matchfuzzypos matchlist 
matchstr matchstrlist matchstrpos max menu_info min mkdir mode mzeval 
nextnonblank nr2char or pathshorten perleval popup_atcursor popup_beval 
popup_clear popup_close popup_create popup_dialog popup_filter_menu 
popup_filter_yesno popup_findecho
-syn keyword vimFuncName contained popup_findinfo popup_findpreview 
popup_getoptions popup_getpos popup_hide popup_list popup_locate popup_menu 
popup_move popup_notification popup_setoptions popup_settext popup_show pow 
prevnonblank printf prompt_getprompt prompt_setcallback prompt_setinterrupt 
prompt_setprompt prop_add prop_add_list prop_clear prop_find prop_list 
prop_remove prop_type_add prop_type_change prop_type_delete prop_type_get 
prop_type_list pum_getpos pumvisible py3eval pyeval pyxeval rand range readblob 
readdir readdirex readfile reduce reg_executing reg_recording reltime 
reltimefloat reltimestr remote_expr remote_foreground remote_peek remote_read 
remote_send remote_startserver remove rename repeat resolve reverse round 
rubyeval screenattr screenchar
-syn keyword vimFuncName contained screenchars screencol screenpos screenrow 
screenstring search searchcount searchdecl searchpair searchpairpos searchpos 
server2client serverlist setbufline setbufvar setcellwidths setcharpos 
setcharsearch setcmdline setcmdpos setcursorcharpos setenv setfperm setline 
setloclist setmatches setpos setqflist setreg settabvar settabwinvar 
settagstack setwinvar sha256 shellescape shiftwidth sign_define sign_getdefined 
sign_getplaced sign_jump sign_place sign_placelist sign_undefine sign_unplace 
sign_unplacelist simplify sin sinh slice sort sound_clear sound_playevent 
sound_playfile sound_stop soundfold spellbadword spellsuggest split sqrt srand 
state str2float str2list str2nr strcharlen strcharpart strchars strdisplaywidth 
strftime
-syn keyword vimFuncName contained strgetchar stridx string strlen strpart 
strptime strridx strtrans strutf16len strwidth submatch substitute swapfilelist 
swapinfo swapname synID synIDattr synIDtrans synconcealed synstack system 
systemlist tabpagebuflist tabpagenr tabpagewinnr tagfiles taglist tan tanh 
tempname term_dumpdiff term_dumpload term_dumpwrite term_getaltscreen 
term_getansicolors term_getattr term_getcursor term_getjob term_getline 
term_getscrolled term_getsize term_getstatus term_gettitle term_gettty 
term_list term_scrape term_sendkeys term_setansicolors term_setapi term_setkill 
term_setrestore term_setsize term_start term_wait terminalprops test_alloc_fail 
test_autochdir test_feedinput test_garbagecollect_now test_garbagecollect_soon 
test_getvalue test_gui_event
-syn keyword vimFuncName contained test_ignore_error test_mswin_event 
test_null_blob test_null_channel test_null_dict test_null_function 
test_null_job test_null_list test_null_partial test_null_string 
test_option_not_set test_override test_refcount test_setmouse test_settime 
test_srand_seed test_unknown test_void timer_info timer_pause timer_start 
timer_stop timer_stopall tolower toupper tr trim trunc type typename undofile 
undotree uniq utf16idx values virtcol virtcol2col visualmode wildmenumode 
win_execute win_findbuf win_getid win_gettype win_gotoid win_id2tabwin 
win_id2win win_move_separator win_move_statusline win_screenpos win_splitmove 
winbufnr wincol windowsversion winheight winlayout winline winnr winrestcmd 
winrestview winsaveview winwidth wordcount writefile
-syn keyword vimFuncName contained xor
+syn keyword vimFuncName contained popup_findinfo popup_findpreview 
popup_getoptions popup_getpos popup_hide popup_list popup_locate popup_menu 
popup_move popup_notification popup_setbuf popup_setoptions popup_settext 
popup_show pow prevnonblank printf prompt_getprompt prompt_setcallback 
prompt_setinterrupt prompt_setprompt prop_add prop_add_list prop_clear 
prop_find prop_list prop_remove prop_type_add prop_type_change prop_type_delete 
prop_type_get prop_type_list pum_getpos pumvisible py3eval pyeval pyxeval rand 
range readblob readdir readdirex readfile reduce reg_executing reg_recording 
reltime reltimefloat reltimestr remote_expr remote_foreground remote_peek 
remote_read remote_send remote_startserver remove rename repeat resolve reverse 
round rubyeval screenattr
+syn keyword vimFuncName contained screenchar screenchars screencol screenpos 
screenrow screenstring search searchcount searchdecl searchpair searchpairpos 
searchpos server2client serverlist setbufline setbufvar setcellwidths 
setcharpos setcharsearch setcmdline setcmdpos setcursorcharpos setenv setfperm 
setline setloclist setmatches setpos setqflist setreg settabvar settabwinvar 
settagstack setwinvar sha256 shellescape shiftwidth sign_define sign_getdefined 
sign_getplaced sign_jump sign_place sign_placelist sign_undefine sign_unplace 
sign_unplacelist simplify sin sinh slice sort sound_clear sound_playevent 
sound_playfile sound_stop soundfold spellbadword spellsuggest split sqrt srand 
state str2float str2list str2nr strcharlen strcharpart strchars strdisplaywidth
+syn keyword vimFuncName contained strftime strgetchar stridx string strlen 
strpart strptime strridx strtrans strutf16len strwidth submatch substitute 
swapfilelist swapinfo swapname synID synIDattr synIDtrans synconcealed synstack 
system systemlist tabpagebuflist tabpagenr tabpagewinnr tagfiles taglist tan 
tanh tempname term_dumpdiff term_dumpload term_dumpwrite term_getaltscreen 
term_getansicolors term_getattr term_getcursor term_getjob term_getline 
term_getscrolled term_getsize term_getstatus term_gettitle term_gettty 
term_list term_scrape term_sendkeys term_setansicolors term_setapi term_setkill 
term_setrestore term_setsize term_start term_wait terminalprops test_alloc_fail 
test_autochdir test_feedinput test_garbagecollect_now test_garbagecollect_soon 
test_getvalue
+syn keyword vimFuncName contained test_gui_event test_ignore_error 
test_mswin_event test_null_blob test_null_channel test_null_dict 
test_null_function test_null_job test_null_list test_null_partial 
test_null_string test_option_not_set test_override test_refcount test_setmouse 
test_settime test_srand_seed test_unknown test_void timer_info timer_pause 
timer_start timer_stop timer_stopall tolower toupper tr trim trunc type 
typename undofile undotree uniq utf16idx values virtcol virtcol2col visualmode 
wildmenumode win_execute win_findbuf win_getid win_gettype win_gotoid 
win_id2tabwin win_id2win win_move_separator win_move_statusline win_screenpos 
win_splitmove winbufnr wincol windowsversion winheight winlayout winline winnr 
winrestcmd winrestview winsaveview winwidth
+syn keyword vimFuncName contained wordcount writefile xor
 
 "--- syntax here and above generated by mkvimvim ---
 " Special Vim Highlighting (not automatic) {{{1
@@ -315,19 +315,19 @@ syn keyword       vimFuncKey      contained       
fu[nction]
 syn keyword    vimDefKey       contained       def
 syn keyword    vimMethodName   contained       empty len string
 
-syn region     vimFuncParams   contained       matchgroup=Delimiter start="(" 
skip=+
\s*\\|
\s*"\ + end=")" skipwhite skipnl 
nextgroup=vimFuncBody,vimFuncComment,vimEndfunction,vimFuncMod 
contains=vimFuncParam,@vimContinue
-syn region     vimDefParams    contained       matchgroup=Delimiter start="("  
           end=")" skipwhite skipnl 
nextgroup=vimDefBody,vimDefComment,vimEnddef,vimReturnType   
contains=vimDefParam,vim9Comment
+syn region     vimFuncParams   contained       matchgroup=Delimiter start="(" 
skip=+
\s*\\|
\s*"\ + end=")" skipwhite skipnl 
nextgroup=vimFuncBody,vimFuncComment,vimEndfunction,vimFuncMod,vim9CommentError 
       contains=vimFuncParam,@vimContinue
+syn region     vimDefParams    contained       matchgroup=Delimiter start="("  
           end=")" skipwhite skipnl 
nextgroup=vimDefBody,vimDefComment,vimEnddef,vimReturnType,vimCommentError  
contains=vimDefParam,vim9Comment
 syn match      vimFuncParam    contained       "\<\h\w*\>\|\.\.\."     
skipwhite nextgroup=vimFuncParamEquals
 syn match      vimDefParam     contained       "\<\h\w*\>"             
skipwhite nextgroup=vimParamType,vimFuncParamEquals
 
 syn match      vimFuncParamEquals contained    "="                     
skipwhite        nextgroup=@vimExprList
-syn match      vimFuncMod       contained      
"\<\%(abort\|closure\|dict\|range\)\>"  skipwhite skipnl 
nextgroup=vimFuncBody,vimFuncComment,vimEndfunction,vimFuncMod
+syn match      vimFuncMod       contained      
"\<\%(abort\|closure\|dict\|range\)\>"  skipwhite skipnl 
nextgroup=vimFuncBody,vimFuncComment,vimEndfunction,vimFuncMod,vim9CommentError
 
-syn region     vimFuncBody     contained       start="^"       
matchgroup=vimCommand end="\<endfu\%[nction]\>" contains=@vimFuncBodyList
-syn region     vimDefBody      contained       start="^"       
matchgroup=vimCommand end="\<enddef\>"  contains=@vimDefBodyList
+syn region     vimFuncBody     contained       start="^.\="    
matchgroup=vimCommand end="\<endfu\%[nction]\>" contains=@vimFuncBodyList 
skipwhite nextgroup=vimCmdSep,vimComment,vim9CommentError
+syn region     vimDefBody      contained       start="^.\="    
matchgroup=vimCommand end="\<enddef\>"  contains=@vimDefBodyList  skipwhite 
nextgroup=vimCmdSep,vim9Comment,vimCommentError
 
-syn match      vimEndfunction  "\<endf\%[unction]\>"
-syn match      vimEnddef       "\<enddef\>"
+syn match      vimEndfunction  "\<endf\%[unction]\>" skipwhite 
nextgroup=vimCmdSep,vimComment,vim9CommentError
+syn match      vimEnddef       "\<enddef\>"        skipwhite 
nextgroup=vimCmdSep,vim9Comment,vimCommentError
 
 if exists("g:vimsyn_folding") && g:vimsyn_folding =~# 'f'
  syn region    vimFuncFold     
start="^\s*:\=\s*fu\%[nction]\>!\=\s*\%(<[sS][iI][dD]>\|[sg]:\)\=\%(\i\|[#.]\|{.\{-1,}}\)\+\s*("
        end="^\s*:\=\s*endf\%[unction]\>" contains=vimFunction fold keepend 
extend transparent
@@ -341,7 +341,7 @@ syn match   vimFuncBlank contained  "\s\+"
 " Types: {{{2
 " =====
 " vimTypes : new for vim9
-syn region     vimReturnType   contained       start=":\s" end="$" 
matchgroup=vim9Comment end="\ze#" skipwhite skipnl 
nextgroup=vimDefBody,vimDefComment,vimEnddef contains=vimTypeSep transparent
+syn region     vimReturnType   contained       start=":\s" end="$" 
matchgroup=vim9Comment end="\ze[#"]" skipwhite skipnl 
nextgroup=vimDefBody,vimDefComment,vimEnddef,vimCommentError 
contains=vimTypeSep transparent
 syn match      vimParamType    contained       ":\s\+ "                        
skipwhite skipnl nextgroup=vimFuncParamEquals                   
contains=vimTypeSep,@vimType
 
 syn match      vimTypeSep      contained       ":\s\@=" skipwhite 
nextgroup=@vimType
@@ -447,6 +447,9 @@ else
   syn cluster vimComment contains=vimComment
 endif
 
+syn match      vim9CommentError        contained       "#.*"
+syn match      vimCommentError contained       +".*+
+
 " Environment Variables: {{{2
 " =====================
 syn match      vimEnvvar       "\$\I\i*"
@@ -919,12 +922,12 @@ endif
 " Allows users to specify the type of embedded script highlighting
 " they want:  (perl/python/ruby/tcl support)
 "   g:vimsyn_embed == 0   : don't embed any scripts
-"   g:vimsyn_embed =~# 'l' : embed lua      (but only if vim supports it)
-"   g:vimsyn_embed =~# 'm' : embed mzscheme (but only if vim supports it)
-"   g:vimsyn_embed =~# 'p' : embed perl     (but only if vim supports it)
-"   g:vimsyn_embed =~# 'P' : embed python   (but only if vim supports it)
-"   g:vimsyn_embed =~# 'r' : embed ruby     (but only if vim supports it)
-"   g:vimsyn_embed =~# 't' : embed tcl      (but only if vim supports it)
+"   g:vimsyn_embed =~# 'l' : embed Lua      (but only if vim supports it)
+"   g:vimsyn_embed =~# 'm' : embed MzScheme (but only if vim supports it)
+"   g:vimsyn_embed =~# 'p' : embed Perl     (but only if vim supports it)
+"   g:vimsyn_embed =~# 'P' : embed Python   (but only if vim supports it)
+"   g:vimsyn_embed =~# 'r' : embed Ruby     (but only if vim supports it)
+"   g:vimsyn_embed =~# 't' : embed Tcl      (but only if vim supports it)
 if !exists("g:vimsyn_embed")
  let g:vimsyn_embed= "lmpPr"
 endif
@@ -1136,7 +1139,9 @@ if !exists("skip_vim_syntax_inits")
  hi def link vimCmplxRepeat    SpecialChar
  hi def link vimCommand        Statement
  hi def link vimComment        Comment
+ hi def link vimCommentError   vimError
  hi def link vim9Comment       Comment
+ hi def link vim9CommentError  vimError
  hi def link vimCommentString  vimString
  hi def link vimCommentTitle   PreProc
  hi def link vim9CommentTitle  PreProc
@@ -1145,7 +1150,7 @@ if !exists("skip_vim_syntax_inits")
  hi def link vimContinue       Special
  hi def link vimContinueComment        vimComment
  hi def link vimCtrlChar       SpecialChar
- hi def link vimDefComment     vimComment
+ hi def link vimDefComment     vim9Comment
  hi def link vimDefKey vimCommand
  hi def link vimDefParam vimVar
  hi def link vimEcho   vimCommand

-- 
-- 
You received this message from the "vim_dev" maillist.
Do not top-post! Type your reply below the text you are replying to.
For more information, visit http://www.vim.org/maillist.php

--- 
You received this message because you are subscribed to the Google Groups 
"vim_dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to vim_dev+unsubscr...@googlegroups.com.
To view this discussion on the web visit 
https://groups.google.com/d/msgid/vim_dev/E1sKx4P-00AaHM-UH%40256bit.org.

Raspunde prin e-mail lui