vim-patch:8.2.3940: match highlight disappears when doing incsearch for ":s/pat"

Problem:    Match highlight disappears when doing incsearch for ":s/pat".
Solution:   Only use line limit for incsearch highlighting. (closes vim/vim#9425)

94fb8274ca

Co-authored-by: Bram Moolenaar <Bram@vim.org>

src/nvim/match.c

@@ -425,7 +425,7 @@ static void next_search_hl(win_T *win, match_T *search_hl, match_T *shl, linenr_
   const int called_emsg_before = called_emsg;
 
   // for :{range}s/pat only highlight inside the range
-  if (lnum < search_first_line || lnum > search_last_line) {
+  if ((lnum < search_first_line || lnum > search_last_line) && cur == NULL) {
     shl->lnum = 0;
     return;
   }

src/nvim/testdir/test_match.vim

@@ -380,6 +380,27 @@ func Test_match_in_linebreak()
   call delete('XscriptMatchLinebreak')
 endfunc
 
+func Test_match_with_incsearch()
+  CheckRunVimInTerminal
+
+  let lines =<< trim END
+    set incsearch
+    call setline(1, range(20))
+    call matchaddpos('ErrorMsg', [3])
+  END
+  call writefile(lines, 'XmatchWithIncsearch')
+  let buf = RunVimInTerminal('-S XmatchWithIncsearch', #{rows: 6})
+  call TermWait(buf)
+  call VerifyScreenDump(buf, 'Test_match_with_incsearch_1', {})
+
+  call term_sendkeys(buf, ":s/0")
+  call VerifyScreenDump(buf, 'Test_match_with_incsearch_2', {})
+
+  call term_sendkeys(buf, "\<CR>")
+  call StopVimInTerminal(buf)
+  call delete('XmatchWithIncsearch')
+endfunc
+
 " Test for deleting matches outside of the screen redraw top/bottom lines
 " This should cause a redraw of those lines.
 func Test_matchdelete_redraw()