patch 7.4.2007
Problem:    Running the tests leaves a viminfo file behind.
Solution:   Make the viminfo option empty.
diff --git a/src/testdir/runtest.vim b/src/testdir/runtest.vim
index 57edcc1..c094da0 100644
--- a/src/testdir/runtest.vim
+++ b/src/testdir/runtest.vim
@@ -149,6 +149,9 @@
   endif
 endfor
 
+" Don't write viminfo on exit.
+set viminfo=
+
 if s:fail == 0
   " Success, create the .res file so that make knows it's done.
   exe 'split ' . fnamemodify(g:testname, ':r') . '.res'