patch 8.2.1917: no test for improved Man command

Problem:    No test for improved Man command.
Solution:   Test that shell arguments are properly escaped.
diff --git a/src/testdir/test_man.vim b/src/testdir/test_man.vim
index d2f48e8..f3af477 100644
--- a/src/testdir/test_man.vim
+++ b/src/testdir/test_man.vim
@@ -132,4 +132,18 @@
   %bw!
 endfunc
 
+" Check that underlying shell command arguments are escaped.
+func Test_Man_uses_shellescape()
+  Man `touch\ Xbar` `touch\ Xfoo`
+
+  redir => msg
+  1messages
+  redir END
+  call assert_match('no manual entry for "`touch Xfoo`"', msg)
+
+  call assert_false(filereadable('Xbar'))
+  call assert_false(filereadable('Xfoo'))
+endfunc
+
+
 " vim: shiftwidth=2 sts=2 expandtab