patch 8.2.0576: some errors are not covered by tests
Problem: Some errors are not covered by tests.
Solution: Add a few more tests. (Dominique Pelle, closes #5920)
diff --git a/src/testdir/test_messages.vim b/src/testdir/test_messages.vim
index 90d0d20..32ffb48 100644
--- a/src/testdir/test_messages.vim
+++ b/src/testdir/test_messages.vim
@@ -40,6 +40,8 @@
finally
let &more = oldmore
endtry
+
+ call assert_fails('message 1', 'E474:')
endfunction
" Patch 7.4.1696 defined the "clearmode()" function for clearing the mode