patch 8.2.4865: :startinsert right after :stopinsert may not work

Problem:    :startinsert right after :stopinsert does not work when popup menu
            is still visible.
Solution:   Use ins_compl_active() instead of pum_visible(). (closes #10352)

src/edit.c

@@ -448,7 +448,7 @@ edit(
 	if (update_Insstart_orig)
 	    Insstart_orig = Insstart;
 
-	if (stop_insert_mode && !pum_visible())
+	if (stop_insert_mode && !ins_compl_active())
 	{
 	    // ":stopinsert" used or 'insertmode' reset
 	    count = 0;

src/testdir/test_ins_complete.vim

@@ -555,6 +555,15 @@ func Test_pum_stopped_by_timer()
   call delete('Xpumscript')
 endfunc
 
+func Test_complete_stopinsert_startinsert()
+  nnoremap <F2> <Cmd>startinsert<CR>
+  inoremap <F2> <Cmd>stopinsert<CR>
+  " This just checks if this causes an error
+  call feedkeys("i\<C-X>\<C-N>\<F2>\<F2>", 'x')
+  nunmap <F2>
+  iunmap <F2>
+endfunc
+
 func Test_pum_with_folds_two_tabs()
   CheckScreendump
 

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4865,
 /**/
     4864,
 /**/