vim-patch:8.2.4018: ml_get error when win_execute redraws with Visual selection

Problem:    ml_get error when win_execute redraws with Visual selection.
Solution:   Disable Visual area temporarily. (closes vim/vim#9479)
https://github.com/vim/vim/commit/18f4740f043b353abe47b7a00131317052457686

{switch_to/restore}_win_for_buf is N/A (marked as such in v8.0.0860; currently
only used in Vim's if_py).

Add a modeline to test_execute_func.vim.

1 files changed, 9 insertions, 14 deletions

diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index 29619f62e9..3cfc00fea2 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -2176,20 +2176,18 @@ static void f_win_execute(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
   tabpage_T *tp;
   win_T *wp = win_id2wp_tp(argvars, &tp);
-  win_T *save_curwin;
-  tabpage_T *save_curtab;
   // Return an empty string if something fails.
   rettv->v_type = VAR_STRING;
   rettv->vval.v_string = NULL;
 
   if (wp != NULL && tp != NULL) {
     pos_T curpos = wp->w_cursor;
-    if (switch_win_noblock(&save_curwin, &save_curtab, wp, tp, true) ==
-        OK) {
+    switchwin_T switchwin;
+    if (switch_win_noblock(&switchwin, wp, tp, true) == OK) {
       check_cursor();
       execute_common(argvars, rettv, fptr, 1);
     }
-    restore_win_noblock(save_curwin, save_curtab, true);
+    restore_win_noblock(&switchwin, true);
 
     // Update the status line if the cursor moved.
     if (win_valid(wp) && !equalpos(curpos, wp->w_cursor)) {
@@ -4031,8 +4029,6 @@ static void f_gettabinfo(typval_T *argvars, typval_T *rettv, FunPtr fptr)
  */
 static void f_gettabvar(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  win_T *oldcurwin;
-  tabpage_T *oldtabpage;
   bool done = false;
 
   rettv->v_type = VAR_STRING;
@@ -4046,7 +4042,8 @@ static void f_gettabvar(typval_T *argvars, typval_T *rettv, FunPtr fptr)
     win_T *const window = tp == curtab || tp->tp_firstwin == NULL
         ? firstwin
         : tp->tp_firstwin;
-    if (switch_win(&oldcurwin, &oldtabpage, window, tp, true) == OK) {
+    switchwin_T switchwin;
+    if (switch_win(&switchwin, window, tp, true) == OK) {
       // look up the variable
       // Let gettabvar({nr}, "") return the "t:" dictionary.
       const dictitem_T *const v = find_var_in_ht(&tp->tp_vars->dv_hashtab, 't',
@@ -4059,7 +4056,7 @@ static void f_gettabvar(typval_T *argvars, typval_T *rettv, FunPtr fptr)
     }
 
     // restore previous notion of curwin
-    restore_win(oldcurwin, oldtabpage, true);
+    restore_win(&switchwin, true);
   }
 
   if (!done && argvars[2].v_type != VAR_UNKNOWN) {
@@ -5881,18 +5878,16 @@ static void f_line(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 
   if (argvars[1].v_type != VAR_UNKNOWN) {
     tabpage_T *tp;
-    win_T *save_curwin;
-    tabpage_T *save_curtab;
 
     // use window specified in the second argument
     win_T *wp = win_id2wp_tp(&argvars[1], &tp);
     if (wp != NULL && tp != NULL) {
-      if (switch_win_noblock(&save_curwin, &save_curtab, wp, tp, true)
-          == OK) {
+      switchwin_T switchwin;
+      if (switch_win_noblock(&switchwin, wp, tp, true) == OK) {
         check_cursor();
         fp = var2fpos(&argvars[0], true, &fnum);
       }
-      restore_win_noblock(save_curwin, save_curtab, true);
+      restore_win_noblock(&switchwin, true);
     }
   } else {
     // use current window