Avoid that running tests changes viminfo.
diff --git a/src/testdir/test29.in b/src/testdir/test29.in
index 829961c..6c7d3d5 100644
--- a/src/testdir/test29.in
+++ b/src/testdir/test29.in
@@ -4,7 +4,7 @@
  and with 'cpoptions' flag 'j' set or not
 
 STARTTEST
-:set nocompatible
+:set nocompatible viminfo+=nviminfo
 :set nojoinspaces
 :set cpoptions-=j
 /firstline/