vim-patch:8.2.2631: commands from winrestcmd() do not always work properly

Problem:    Commands from winrestcmd() do not always work properly. (Leonid V.
            Fedorenchik)
Solution:   Repeat the size commands twice. (closes vim/vim#7988)
a0c8aea479

src/nvim/eval/funcs.c

@@ -11378,17 +11378,23 @@ static void f_winnr(typval_T *argvars, typval_T *rettv, FunPtr fptr)
  */
 static void f_winrestcmd(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  int winnr = 1;
   garray_T ga;
   char_u buf[50];
 
   ga_init(&ga, (int)sizeof(char), 70);
+
+  // Do this twice to handle some window layouts properly.
+  for (int i = 0; i < 2; i++) {
+    int winnr = 1;
     FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
-    sprintf((char *)buf, "%dresize %d|", winnr, wp->w_height);
+      snprintf((char *)buf, sizeof(buf), "%dresize %d|", winnr,
+               wp->w_height);
       ga_concat(&ga, buf);
-    sprintf((char *)buf, "vert %dresize %d|", winnr, wp->w_width);
+      snprintf((char *)buf, sizeof(buf), "vert %dresize %d|", winnr,
+               wp->w_width);
       ga_concat(&ga, buf);
-    ++winnr;
+      winnr++;
+    }
   }
   ga_append(&ga, NUL);
 

src/nvim/testdir/test_window_cmd.vim

@@ -550,16 +550,29 @@ endfunc
 func Test_winrestcmd()
   2split
   3vsplit
-  let a = winrestcmd()
+  let restcmd = winrestcmd()
   call assert_equal(2, winheight(0))
   call assert_equal(3, winwidth(0))
   wincmd =
   call assert_notequal(2, winheight(0))
   call assert_notequal(3, winwidth(0))
-  exe a
+  exe restcmd
   call assert_equal(2, winheight(0))
   call assert_equal(3, winwidth(0))
   only
+
+  wincmd v
+  wincmd s
+  wincmd v
+  redraw
+  let restcmd = winrestcmd()
+  wincmd _
+  wincmd |
+  exe restcmd
+  redraw
+  call assert_equal(restcmd, winrestcmd())
+
+  only
 endfunc
 
 function! Fun_RenewFile()