patch 9.1.1465: tabpanel: not correctly drawn with 'equalalways'

Problem:  tabpanel: not correctly drawn with 'equalalways'
Solution: call win_equal() (Hirohito Higashi)

closes: #17554

Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_tabpanel.vim b/src/testdir/test_tabpanel.vim
index 1790fee..4d2fca1 100644
--- a/src/testdir/test_tabpanel.vim
+++ b/src/testdir/test_tabpanel.vim
@@ -26,6 +26,14 @@
   call VerifyScreenDump(buf, 'Test_tabpanel_stpl_eq_0_0', {})
   call term_sendkeys(buf, ":tabnext\<CR>\<C-L>")
   call VerifyScreenDump(buf, 'Test_tabpanel_stpl_eq_0_1', {})
+  call term_sendkeys(buf, ":set showtabpanel=2\<CR>")
+  call term_sendkeys(buf, ":vsp aaa\<CR>:vsp bbb\<CR>\<C-L>")
+  call VerifyScreenDump(buf, 'Test_tabpanel_stpl_eq_0_2', {})
+  call term_sendkeys(buf, ":set showtabpanel=0\<CR>\<C-L>")
+  call VerifyScreenDump(buf, 'Test_tabpanel_stpl_eq_0_3', {})
+  call term_sendkeys(buf, ":wincmd |\<CR>")
+  call term_sendkeys(buf, ":set showtabpanel=2\<CR>\<C-L>")
+  call VerifyScreenDump(buf, 'Test_tabpanel_stpl_eq_0_2', {})
   call StopVimInTerminal(buf)
 endfunc