patch 9.0.1855: mode() doesn't indicate command line for terminal

Problem:  mode() doesn't indicate command line for terminal
Solution: make it return 'ct' for command-line from Terminal mode

closes: #6265
closes: #13017
closes: #13018

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: h-east <h.east.727@gmail.com>
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index ab1dbf3..654d912 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -935,9 +935,19 @@
 
   if has('terminal')
     term
+    " Terminal-Job mode
+    call assert_equal('t', mode())
+    call assert_equal('t', mode(1))
+    call feedkeys("\<C-W>:echo \<C-R>=Save_mode()\<C-U>\<CR>", 'xt')
+    call assert_equal("c-ct", g:current_modes)
+    call feedkeys("\<Esc>", 'xt')
+
+    " Terminal-Normal mode
     call feedkeys("\<C-W>N", 'xt')
     call assert_equal('n', mode())
     call assert_equal('nt', mode(1))
+    call feedkeys(":echo \<C-R>=Save_mode()\<C-U>\<CR>", 'xt')
+    call assert_equal("c-c", g:current_modes)
     call feedkeys("aexit\<CR>", 'xt')
   endif