diff -up ghostscript-8.63/src/iname.c.465311 ghostscript-8.63/src/iname.c --- ghostscript-8.63/src/iname.c.465311 2008-10-17 11:52:31.000000000 +0100 +++ ghostscript-8.63/src/iname.c 2008-10-17 11:53:08.000000000 +0100 @@ -415,7 +415,8 @@ names_trace_finish(name_table * nt, gc_s if (nt->sub[i].names == 0 && gcst != 0) { /* Mark the just-freed sub-table as unmarked. */ o_set_unmarked((obj_header_t *)sub - 1); - o_set_unmarked((obj_header_t *)ssub - 1); + if (ssub != 0) + o_set_unmarked((obj_header_t *)ssub - 1); } } if (i == 0)