vim-patch:8.2.2447: 'foldlevel' not applied to folds restored from session

Problem:    'foldlevel' not applied to folds restored from session.
Solution:   Set 'foldlevel' after creaiting the folds. (closes vim/vim#7767)
f9547eb6ef

src/nvim/fold.c

@@ -2999,7 +2999,6 @@ static void foldlevelDiff(fline_T *flp)
 static void foldlevelExpr(fline_T *flp)
 {
   win_T       *win;
-  int n;
   int c;
   linenr_T lnum = flp->lnum + flp->off;
 
@@ -3017,7 +3016,7 @@ static void foldlevelExpr(fline_T *flp)
   /* KeyTyped may be reset to 0 when calling a function which invokes
    * do_cmdline().  To make 'foldopen' work correctly restore KeyTyped. */
   const bool save_keytyped = KeyTyped;
-  n = (int)eval_foldexpr(flp->wp->w_p_fde, &c);
+  const int n = eval_foldexpr(flp->wp->w_p_fde, &c);
   KeyTyped = save_keytyped;
 
   switch (c) {
@@ -3202,8 +3201,10 @@ int put_folds(FILE *fd, win_T *wp)
 {
   if (foldmethodIsManual(wp)) {
     if (put_line(fd, "silent! normal! zE") == FAIL
-        || put_folds_recurse(fd, &wp->w_folds, (linenr_T)0) == FAIL)
+        || put_folds_recurse(fd, &wp->w_folds, (linenr_T)0) == FAIL
+        || put_line(fd, "let &fdl = &fdl") == FAIL) {
       return FAIL;
+    }
   }
 
   /* If some folds are manually opened/closed, need to restore that. */

src/nvim/testdir/test_mksession.vim

@@ -291,6 +291,32 @@ endfunc
 
 endif
 
+func Test_mkview_open_folds()
+  enew!
+
+  call append(0, ['a', 'b', 'c'])
+  1,3fold
+  " zR affects 'foldlevel', make sure the option is applied after the folds
+  " have been recreated.
+  normal zR
+  write! Xtestfile
+
+  call assert_equal(-1, foldclosed(1))
+  call assert_equal(-1, foldclosed(2))
+  call assert_equal(-1, foldclosed(3))
+
+  mkview! Xtestview
+  source Xtestview
+
+  call assert_equal(-1, foldclosed(1))
+  call assert_equal(-1, foldclosed(2))
+  call assert_equal(-1, foldclosed(3))
+
+  call delete('Xtestview')
+  call delete('Xtestfile')
+  %bwipe
+endfunc
+
 " Test :mkview with a file argument.
 func Test_mkview_file()
   " Create a view with line number and a fold.