patch 8.2.2685: custom statusline not drawn correctly with WinBar

Problem:    Custom statusline not drawn correctly with WinBar.
Solution:   Also adjust the column for the custom status line. (Yee Cheng
            Chin, closes #8047)
diff --git a/src/testdir/dumps/Test_winbar_not_visible_custom_statusline.dump b/src/testdir/dumps/Test_winbar_not_visible_custom_statusline.dump
new file mode 100644
index 0000000..9eff5ba
--- /dev/null
+++ b/src/testdir/dumps/Test_winbar_not_visible_custom_statusline.dump
@@ -0,0 +1,10 @@
+|a+1&#ffffff0|b|c|d|e| @69
+> +0&&@74
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|a+3#0000000&|b|c|d|e| @69
+| +0&&@74
diff --git a/src/testdir/test_winbar.vim b/src/testdir/test_winbar.vim
index 2cbdd01..92da312 100644
--- a/src/testdir/test_winbar.vim
+++ b/src/testdir/test_winbar.vim
@@ -141,4 +141,24 @@
   call delete('XtestWinbarNotVisble')
 endfunction
 
+func Test_winbar_not_visible_custom_statusline()
+  CheckScreendump
+
+  let lines =<< trim END
+      split
+      nnoremenu WinBar.Test :test
+      set winminheight=0
+      set statusline=abcde
+      wincmd j
+      wincmd _
+  END
+  call writefile(lines, 'XtestWinbarNotVisble')
+  let buf = RunVimInTerminal('-S XtestWinbarNotVisble', #{rows: 10})
+  call VerifyScreenDump(buf, 'Test_winbar_not_visible_custom_statusline', {})
+
+  " clean up
+  call StopVimInTerminal(buf)
+  call delete('XtestWinbarNotVisble')
+endfunction
+
 " vim: shiftwidth=2 sts=2 expandtab