# 
# patch "roster4.cc"
#  from [9c9f7e81b107f04d7d88665e3abf1993e1cfccbe]
#    to [62bff556976d0137b764a869b4a50c515b1080b3]
# 
========================================================================
--- roster4.cc	9c9f7e81b107f04d7d88665e3abf1993e1cfccbe
+++ roster4.cc	62bff556976d0137b764a869b4a50c515b1080b3
@@ -2059,10 +2059,14 @@
   make_fake_marking_for(a2, a2_map);
   make_fake_marking_for(b, b_map);
   make_fake_marking_for(b2, b2_map);
-  write_roster_and_marking(a, a_map, a_dat, false);
-  write_roster_and_marking(a2, a2_map, a2_dat, false);
-  write_roster_and_marking(b, b_map, b_dat, false);
-  write_roster_and_marking(b2, b2_map, b2_dat, false);
+  if (a.has_root())
+    write_roster_and_marking(a, a_map, a_dat, false);
+  if (a2.has_root())
+    write_roster_and_marking(a2, a2_map, a2_dat, false);
+  if (b.has_root())
+    write_roster_and_marking(b, b_map, b_dat, false);
+  if (b2.has_root())
+    write_roster_and_marking(b2, b2_map, b2_dat, false);
   I(a_dat == a2_dat);
   I(b_dat == b2_dat);