fix #497: Stop VM execution after thread kills itself

Author: adazem009

src/engine/virtualmachine_p.cpp

@@ -781,6 +781,14 @@ unsigned int *VirtualMachinePrivate::run(unsigned int *pos, bool reset)
             DISPATCH(); // this avoids freeing registers after "stopping" a warp script
         }
         FREE_REGS(ret);
+
+        if (atEnd) {
+            if (regCount > 0)
+                std::cout << "warning: VM: " << regCount << " registers were leaked by the script; this is most likely a bug in the VM or in the compiler" << std::endl;
+
+            return pos;
+        }
+
         DISPATCH();
     }
 

test/virtual_machine/virtual_machine_test.cpp

@@ -1773,3 +1773,24 @@ TEST(VirtualMachineTest, NoCrashWhenReadingProcedureArgsAfterStopping)
     ASSERT_EQ(vm.registerCount(), 0);
     ASSERT_TRUE(vm.atEnd());
 }
+
+unsigned int killTest(VirtualMachine *vm)
+{
+    vm->kill();
+    return 1;
+}
+
+TEST(VirtualMachineTest, StopAfterKilled)
+{
+    // Regtest for #497
+    static unsigned int bytecode[] = { OP_START, OP_NULL, OP_EXEC, 0, OP_NULL, OP_NULL, OP_HALT };
+    static BlockFunc functions[] = { &killTest };
+
+    VirtualMachine vm;
+    vm.setBytecode(bytecode);
+    vm.setFunctions(functions);
+
+    vm.run();
+    ASSERT_TRUE(vm.atEnd());
+    ASSERT_EQ(vm.registerCount(), 0);
+}