vim-patch:9.1.0169: current window number returned by tabpagewinnr may be outdated

Problem:  current window number returned by tabpagewinnr may be outdated
          when called from win_execute for the original tabpage.
Solution: update the original tabpage's tp_curwin in switch_win; use
          {un}use_tabpage instead. Don't do it in restore_win to ensure
          tp_curwin of the temporarily visited tabpage is unchanged from
          switch_win visiting it, as before. (Sean Dewar)

Maybe restore_win should only restore tp_curwin if
`curtab == switchwin->sw_curtab`, in case the user changed tabpages from within
win_execute, but not doing that is consistent with the old behaviour.

related: vim/vim#14186

e101028a5c

test/old/testdir/test_execute_func.vim

@@ -212,4 +212,28 @@ func Test_execute_cmd_with_null()
   endif
 endfunc
 
+func Test_win_execute_tabpagewinnr()
+  belowright split
+  tab split
+  belowright split
+  call assert_equal(2, tabpagewinnr(1))
+
+  tabprevious
+  wincmd p
+  call assert_equal(1, tabpagenr())
+  call assert_equal(1, tabpagewinnr(1))
+  call assert_equal(2, tabpagewinnr(2))
+
+  call win_execute(win_getid(1, 2),
+        \      'call assert_equal(2, tabpagenr())'
+        \ .. '| call assert_equal(1, tabpagewinnr(1))'
+        \ .. '| call assert_equal(1, tabpagewinnr(2))')
+
+  call assert_equal(1, tabpagenr())
+  call assert_equal(1, tabpagewinnr(1))
+  call assert_equal(2, tabpagewinnr(2))
+
+  %bwipe!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab