Fix a bug where post-VM gas cost not capped by gas budget (MystenLabs…

…#535)

sui_programmability/adapter/src/adapter.rs

@@ -214,8 +214,22 @@ fn execute_internal<
                 // Cap total_gas by gas_budget in the fail case.
                 return ExecutionStatus::new_failure(cmp::min(total_gas, gas_budget), err);
             }
-            ExecutionStatus::Success {
-                gas_used: total_gas,
+            // gas_budget should be enough to pay not only the VM excution cost,
+            // but also the cost to process all events, such as transfers.
+            if total_gas > gas_budget {
+                ExecutionStatus::new_failure(
+                    gas_budget,
+                    SuiError::InsufficientGas {
+                        error: format!(
+                            "Total gas used ({}) exceeds gas budget ({})",
+                            total_gas, gas_budget
+                        ),
+                    },
+                )
+            } else {
+                ExecutionStatus::Success {
+                    gas_used: total_gas,
+                }
             }
         }
         // charge for all computations so far

sui_programmability/adapter/src/unit_tests/adapter_tests.rs

@@ -478,8 +478,9 @@ fn test_move_call_insufficient_gas() {
     let mut storage = InMemoryStorage::new(genesis_objects);
 
     // 0. Create a gas object for gas payment.
+    let gas_object_id = ObjectID::random();
     let gas_object =
-        Object::with_id_owner_for_testing(ObjectID::random(), base_types::SuiAddress::default());
+        Object::with_id_owner_for_testing(gas_object_id, base_types::SuiAddress::default());
     storage.write_object(gas_object.clone());
     storage.flush();
 
@@ -499,12 +500,30 @@ fn test_move_call_insufficient_gas() {
         20, // This budget is not enough to execute all bytecode.
         Vec::new(),
         Vec::new(),
-        pure_args,
+        pure_args.clone(),
     );
     let err = response.unwrap().unwrap_err();
     assert!(err.1.to_string().contains("VMError with status OUT_OF_GAS"));
     // Provided gas_budget will be deducted as gas.
     assert_eq!(err.0, 20);
+
+    // Trying again with a different gas budget.
+    let gas_object = storage.read_object(&gas_object_id).unwrap();
+    let response = call(
+        &mut storage,
+        &native_functions,
+        "ObjectBasics",
+        "create",
+        gas_object,
+        50, // This budget is enough to execute bytecode, but not enough for processing transfer events.
+        Vec::new(),
+        Vec::new(),
+        pure_args,
+    );
+    let err = response.unwrap().unwrap_err();
+    assert!(matches!(err.1, SuiError::InsufficientGas { .. }));
+    // Provided gas_budget will be deducted as gas.
+    assert_eq!(err.0, 50);
 }
 
 #[test]