patch 9.1.1203: matchparen keeps cursor on case label in sh filetype

Problem:  matchparen keeps cursor on case label in sh filetype
          (@categorical, after 9.1.1187).
Solution: Use :defer so that cursor is always restored, remove checks
          for older Vims, finish early if Vim does not support :defer

fixes: #16887
closes: #16888

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/plugin/matchparen.vim

@@ -1,12 +1,14 @@
 " Vim plugin for showing matching parens
 " Maintainer:	The Vim Project <https://github.com/vim/vim>
-" Last Change:	2025 Mar 08
+" Last Change:	2025 Mar 14
 " Former Maintainer:	Bram Moolenaar <Bram@vim.org>
 
 " Exit quickly when:
 " - this plugin was already loaded (or disabled)
 " - when 'compatible' is set
-if exists("g:loaded_matchparen") || &cp
+" - Vim has no support for :defer
+if exists("g:loaded_matchparen") || &cp ||
+      \ exists(":defer") != 2
   finish
 endif
 let g:loaded_matchparen = 1
@@ -21,17 +23,13 @@ if !exists("g:matchparen_disable_cursor_hl")
   let g:matchparen_disable_cursor_hl = 0
 endif
 
-let s:has_matchaddpos = exists('*matchaddpos')
-
 augroup matchparen
   " Replace all matchparen autocommands
   autocmd! CursorMoved,CursorMovedI,WinEnter,WinScrolled * call s:Highlight_Matching_Pair()
   autocmd! BufWinEnter * autocmd SafeState * ++once call s:Highlight_Matching_Pair()
   autocmd! WinLeave,BufLeave * call s:Remove_Matches()
-  if exists('##TextChanged')
   autocmd! TextChanged,TextChangedI * call s:Highlight_Matching_Pair()
   autocmd! TextChangedP * call s:Remove_Matches()
-  endif
 augroup END
 
 " Skip the rest if it was already done.
@@ -97,14 +95,9 @@ func s:Highlight_Matching_Pair()
   " Find the match.  When it was just before the cursor move it there for a
   " moment.
   if before > 0
-    let has_getcurpos = exists("*getcurpos")
-    if has_getcurpos
-      " getcurpos() is more efficient but doesn't exist before 7.4.313.
     let save_cursor = getcurpos()
-    else
-      let save_cursor = winsaveview()
-    endif
     call cursor(c_lnum, c_col - before)
+    defer setpos('.', save_cursor)
   endif
 
   if !has("syntax") || !exists("g:syntax_on")
@@ -192,31 +185,13 @@ func s:Highlight_Matching_Pair()
     let [m_lnum, m_col] = searchpairpos(c, '', c2, s_flags, s_skip, stopline)
   endtry
 
-  if before > 0
-    if has_getcurpos
-      call setpos('.', save_cursor)
-    else
-      call winrestview(save_cursor)
-    endif
-  endif
-
   " If a match is found setup match highlighting.
   if m_lnum > 0 && m_lnum >= stoplinetop && m_lnum <= stoplinebottom
-    if s:has_matchaddpos
     if !g:matchparen_disable_cursor_hl
       call add(w:matchparen_ids, matchaddpos('MatchParen', [[c_lnum, c_col - before], [m_lnum, m_col]], 10))
     else
       call add(w:matchparen_ids, matchaddpos('MatchParen', [[m_lnum, m_col]], 10))
     endif
-    else
-      if !g:matchparen_disable_cursor_hl
-        exe '3match MatchParen /\(\%' . c_lnum . 'l\%' . (c_col - before) .
-              \ 'c\)\|\(\%' . m_lnum . 'l\%' . m_col . 'c\)/'
-      else
-        exe '3match MatchParen /\(\%' . m_lnum . 'l\%' . m_col . 'c\)/'
-      endif
-      call add(w:matchparen_ids, 3)
-    endif
     let w:paren_hl_on = 1
   endif
 endfunction

src/testdir/dumps/Test_matchparen_sh_case_2.dump

@@ -0,0 +1,10 @@
+|#+0#0000e05#ffffff0|!|/|b|i|n|/|s|h| +0#0000000&@65
+|S+0#00e0e07&|U|S|U|W|U|_|P|R|I|N|T|(|)| |(| +0#0000000&@58
+@2|c+0#af5f00255&|a|s|e| +0#0000000&|"+0#af5f00255&|$+0#e000e06&|{|L|E|V|E|L|}|"+0#af5f00255&| +0#0000000&|i+0#af5f00255&|n| +0#0000000&@54
+@4|"+0#af5f00255&|$+0#e000e06&|S|U|S|U|W|U|_|S|H|_|N|O|T|I|C|E|"+0#af5f00255&|)| +0#0000000&|f|o@1|b|a|r> @43
+@4|$+0#e000e06&|{|S|U|S|U|W|U|_|S|}| +0#0000000&|&+0#af5f00255&@1| +0#0000000&|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|1+0#e000002&| +0#0000000&@47
+@2|;+0#af5f00255&@1| +0#0000000&@70
+@4|"+0#af5f00255&|$+0#e000e06&|S|U|S|U|W|U|_|S|H|_|D|E|B|U|G|"+0#af5f00255&|)| +0#0000000&@51
+@4|(+0#e000e06&|!+0#af5f00255&| +0#0000000&|$+0#e000e06&|{|S|U|S|U|W|U|_|V|E|R|B|O|S|E|}|)| +0#0000000&|&+0#af5f00255&@1| +0#0000000&|r+0#af5f00255&|e|t|u|r|n| +0#0000000&|1+0#e000002&| +0#0000000&@37
+@2|;+0#af5f00255&@1| +0#0000000&@70
+|-+2&&@1| |I|N|S|E|R|T| |-@1| +0&&@44|4|,|3|2| @9|T|o|p| 

src/testdir/test_plugin_matchparen.vim

@@ -168,6 +168,12 @@ func Test_matchparen_ignore_sh_case()
 
   let buf = RunVimInTerminal('-S '.filename, #{rows: 10})
   call VerifyScreenDump(buf, 'Test_matchparen_sh_case_1', {})
+  " Send keys one by one so that CursorMoved is triggered.
+  for c in 'A foobar'
+    call term_sendkeys(buf, c)
+    call term_wait(buf)
+  endfor
+  call VerifyScreenDump(buf, 'Test_matchparen_sh_case_2', {})
   call StopVimInTerminal(buf)
 endfunc
 

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1203,
 /**/
     1202,
 /**/