Fix llvm build break.
diff --git a/toys/pending/ps.c b/toys/pending/ps.c
index cb0f32c..29111d5 100644
--- a/toys/pending/ps.c
+++ b/toys/pending/ps.c
@@ -312,7 +312,7 @@
           if (j!=2) break;
         }
         if (i == ARRAY_LEN(typos)) error_exit("bad -o %.*s", end-type, type);
-        if (!field->title) strcpy(field->title, typos[field->which]);
+        if (!*field->title) strcpy(field->title, typos[field->which]);
         dlist_add_nomalloc((void *)&TT.fields, (void *)field);
       }
     }