patch 8.2.3421: a bit of code is not covered by tests

Problem:    A bit of code is not covered by tests.
Solution:   Add a few more test cases. (Dominique Pellé, closes #8857)
diff --git a/src/testdir/test_startup.vim b/src/testdir/test_startup.vim
index 9872f0b..6b64adf 100644
--- a/src/testdir/test_startup.vim
+++ b/src/testdir/test_startup.vim
@@ -617,7 +617,7 @@
   call assert_equal('More info with: "vim -h"',       out[2])
 
   if has('quickfix')
-    " Detect invalid repeated arguments '-t foo -t foo", '-q foo -q foo'.
+    " Detect invalid repeated arguments '-t foo -t foo', '-q foo -q foo'.
     for opt in ['-t', '-q']
       let out = split(system(GetVimCommand() .. repeat(' ' .. opt .. ' foo', 2)), "\n")
       call assert_equal(1, v:shell_error)
@@ -863,7 +863,7 @@
   call writefile(['    first', '    second', '    third'], 'Xfile1')
 
   for t_arg in ['-t second', '-tsecond']
-    if RunVim(before, after, '-t second')
+    if RunVim(before, after, t_arg)
       call assert_equal(['Xfile1:L2C5'], readfile('Xtestout'), t_arg)
       call delete('Xtestout')
     endif