vim-patch:8.2.4378: incsearch HL broken when calling searchcount in 'tabLine' (#19147)

Problem:    Incsearch highlight broken when calling searchcount() in 'tabLine'
            function. (Mirko Palmer)
Solution:   Save and restore the incsearch state. (Christian Brabandt,
            closes vim/vim#9763, closes vim/vim#9633)
6dd7424c7e

src/nvim/search.c

@@ -286,6 +286,8 @@ static struct spat saved_last_search_spat;
 static int did_save_last_search_spat = 0;
 static int saved_last_idx = 0;
 static bool saved_no_hlsearch = false;
+static colnr_T saved_search_match_endcol;
+static linenr_T saved_search_match_lines;
 
 /// Save and restore the search pattern for incremental highlight search
 /// feature.
@@ -328,6 +330,21 @@ void restore_last_search_pattern(void)
   set_no_hlsearch(saved_no_hlsearch);
 }
 
+/// Save and restore the incsearch highlighting variables.
+/// This is required so that calling searchcount() at does not invalidate the
+/// incsearch highlighting.
+static void save_incsearch_state(void)
+{
+  saved_search_match_endcol = search_match_endcol;
+  saved_search_match_lines  = search_match_lines;
+}
+
+static void restore_incsearch_state(void)
+{
+  search_match_endcol = saved_search_match_endcol;
+  search_match_lines  = saved_search_match_lines;
+}
+
 char_u *last_search_pattern(void)
 {
   return spats[RE_SEARCH].pat;
@@ -4717,6 +4734,7 @@ void f_searchcount(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   }
 
   save_last_search_pattern();
+  save_incsearch_state();
   if (pattern != NULL) {
     if (*pattern == NUL) {
       goto the_end;
@@ -4738,6 +4756,7 @@ void f_searchcount(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 
 the_end:
   restore_last_search_pattern();
+  restore_incsearch_state();
 }
 
 /// Fuzzy string matching

src/nvim/testdir/test_search_stat.vim

@@ -370,6 +370,48 @@ func Test_search_stat_then_gd()
   call delete('Xsearchstatgd')
 endfunc
 
+func Test_search_stat_and_incsearch()
+  CheckScreendump
+
+  let lines =<< trim END
+    call setline(1, ['abc--c', '--------abc', '--abc'])
+    set hlsearch
+    set incsearch
+    set bg=dark
+    set showtabline=2
+
+    function MyTabLine()
+    try
+      let a=searchcount(#{recompute: 1, maxcount: -1})
+      return a.current .. '/' .. a.total
+    catch
+      return ''
+    endtry
+    endfunction
+
+    set tabline=%!MyTabLine()
+  END
+  call writefile(lines, 'Xsearchstat_inc')
+
+  let buf = RunVimInTerminal('-S Xsearchstat_inc', #{rows: 10})
+  call term_sendkeys(buf, "/abc")
+  call TermWait(buf)
+  call VerifyScreenDump(buf, 'Test_searchstat_inc_1', {})
+
+  call term_sendkeys(buf, "\<c-g>")
+  call TermWait(buf)
+  call VerifyScreenDump(buf, 'Test_searchstat_inc_2', {})
+
+  call term_sendkeys(buf, "\<c-g>")
+  call TermWait(buf)
+  call VerifyScreenDump(buf, 'Test_searchstat_inc_3', {})
+
+  call term_sendkeys(buf, "\<esc>:qa\<cr>")
+  call TermWait(buf)
+
+  call StopVimInTerminal(buf)
+  call delete('Xsearchstat_inc')
+endfunc
 
 
 " vim: shiftwidth=2 sts=2 expandtab