patch 8.1.1143: may pass weird strings to file name expansion

Problem:    May pass weird strings to file name expansion.
Solution:   Check for matching characters.  Disallow control characters.
diff --git a/src/testdir/test_escaped_glob.vim b/src/testdir/test_escaped_glob.vim
index 880f32e..a03c180 100644
--- a/src/testdir/test_escaped_glob.vim
+++ b/src/testdir/test_escaped_glob.vim
@@ -17,7 +17,7 @@
   " Setting 'shell' to an invalid name causes a memory leak.
   sandbox call assert_equal("", glob('Xxx\{'))
   sandbox call assert_equal("", glob('Xxx\$'))
-  w! Xxx{
+  w! Xxx\{
   w! Xxx\$
   sandbox call assert_equal("Xxx{", glob('Xxx\{'))
   sandbox call assert_equal("Xxx$", glob('Xxx\$'))
diff --git a/src/testdir/test_spell.vim b/src/testdir/test_spell.vim
index 76ad12e..6bf43ac 100644
--- a/src/testdir/test_spell.vim
+++ b/src/testdir/test_spell.vim
@@ -149,6 +149,12 @@
   set nospell spelllang=en
   call assert_fails('spellinfo', 'E756:')
 
+  call assert_fails('set spelllang=foo/bar', 'E474:')
+  call assert_fails('set spelllang=foo\ bar', 'E474:')
+  call assert_fails("set spelllang=foo\\\nbar", 'E474:')
+  call assert_fails("set spelllang=foo\\\rbar", 'E474:')
+  call assert_fails("set spelllang=foo+bar", 'E474:')
+
   set enc& spell& spelllang&
   bwipe
 endfunc