2 files changed, 7 insertions, 2 deletions
diff --git a/chapter22/src/test/java/com/seaofnodes/simple/Chapter09Test.java b/chapter22/src/test/java/com/seaofnodes/simple/Chapter09Test.java
index d4d02aa9..551880b1 100644
--- a/chapter22/src/test/java/com/seaofnodes/simple/Chapter09Test.java
+++ b/chapter22/src/test/java/com/seaofnodes/simple/Chapter09Test.java
@@ -128,7 +128,7 @@ while(v1+arg) {
 }
                 """);
         code.parse().opto();
-        assertEquals("return Top;", code.print());
+        assertEquals("Stop[ ]", code.print()); // No explicit return: omit default main.
     }
 
     @Test
@@ -210,7 +210,7 @@ return -0+0+0;
     public void testFuzz3() {
         CodeGen code = new CodeGen("int v0=0; while(0==69) while(v0) return 0;");
         code.parse().opto();
-        assertEquals("return 0;", code.print());
+        assertEquals("Stop[ ]", code.print()); // The only return is unreachable.
     }
 
     @Test
diff --git a/chapter22/src/test/java/com/seaofnodes/simple/Chapter20Test.java b/chapter22/src/test/java/com/seaofnodes/simple/Chapter20Test.java
index 1765512a..1f4a3d27 100644
--- a/chapter22/src/test/java/com/seaofnodes/simple/Chapter20Test.java
+++ b/chapter22/src/test/java/com/seaofnodes/simple/Chapter20Test.java
@@ -205,6 +205,11 @@ s.cs[0] =  67; // C
 s.cs[1] = 108; // l
 hashCode(s);
 """;
+        // Without an explicit return, default main must be removed completely.
+        // Seed 0 previously left a loop with a missing branch successor.
+        for( String cpu : new String[]{"x86_64_v2","riscv","arm"} )
+            new CodeGen(src,com.seaofnodes.simple.type.TypeInteger.BOT,0)
+                .driver(CodeGen.Phase.Encoding,cpu,"SystemV");
         testTarget(src,"x86_64_v2", "SystemV",0,null);
         testTarget(src,"riscv"    , "SystemV",0,null);
         testTarget(src,"arm"      , "SystemV",0,null);