allow zero length messages, test for inline failure propagation and empty transaction failure

ref EOSIO/eos#175

contracts/test_api/test_api.cpp

@@ -62,10 +62,13 @@ extern "C" {
 
       //test transaction
       WASM_TEST_HANDLER(test_transaction, send_message);
+      WASM_TEST_HANDLER(test_transaction, send_message_empty);
       WASM_TEST_HANDLER(test_transaction, send_message_max);
       WASM_TEST_HANDLER(test_transaction, send_message_large);
       WASM_TEST_HANDLER(test_transaction, send_message_recurse);
+      WASM_TEST_HANDLER(test_transaction, send_message_inline_fail);
       WASM_TEST_HANDLER(test_transaction, send_transaction);
+      WASM_TEST_HANDLER(test_transaction, send_transaction_empty);
       WASM_TEST_HANDLER(test_transaction, send_transaction_max);
       WASM_TEST_HANDLER(test_transaction, send_transaction_large);
       

contracts/test_api/test_api.hpp

@@ -108,10 +108,13 @@ struct test_crypto {
 struct test_transaction {
 
   static unsigned int send_message();
+  static unsigned int send_message_empty();
   static unsigned int send_message_max();
   static unsigned int send_message_large();
   static unsigned int send_message_recurse();
+  static unsigned int send_message_inline_fail();
   static unsigned int send_transaction();
+  static unsigned int send_transaction_empty();
   static unsigned int send_transaction_max();
   static unsigned int send_transaction_large();
 };

contracts/test_api/test_transaction.cpp

@@ -10,15 +10,9 @@ unsigned int test_transaction::send_message() {
    return WASM_TEST_PASS;
 }
 
-unsigned int test_transaction::send_transaction() {
-   dummy_message payload = {DUMMY_MESSAGE_DEFAULT_A, DUMMY_MESSAGE_DEFAULT_B, DUMMY_MESSAGE_DEFAULT_C};
-   auto msg = messageCreate(N(testapi), WASM_TEST_ACTION("test_message", "read_message"), &payload, sizeof(dummy_message));
-   
-
-   auto trx = transactionCreate();
-   transactionRequireScope(trx, N(testapi));
-   transactionAddMessage(trx, msg);
-   transactionSend(trx);
+unsigned int test_transaction::send_message_empty() {
+   auto msg = messageCreate(N(testapi), WASM_TEST_ACTION("test_message", "assert_true"), nullptr, 0);
+   messageSend(msg);
    return WASM_TEST_PASS;
 }
 
@@ -54,6 +48,34 @@ unsigned int test_transaction::send_message_recurse() {
    return WASM_TEST_PASS;
 }
 
+/**
+ * cause failure due to inline TX failure
+ */
+unsigned int test_transaction::send_message_inline_fail() {
+   auto msg = messageCreate(N(testapi), WASM_TEST_ACTION("test_message", "assert_false"), nullptr, 0);
+   messageSend(msg);
+   return WASM_TEST_PASS;
+}
+
+unsigned int test_transaction::send_transaction() {
+   dummy_message payload = {DUMMY_MESSAGE_DEFAULT_A, DUMMY_MESSAGE_DEFAULT_B, DUMMY_MESSAGE_DEFAULT_C};
+   auto msg = messageCreate(N(testapi), WASM_TEST_ACTION("test_message", "read_message"), &payload, sizeof(dummy_message));
+   
+
+   auto trx = transactionCreate();
+   transactionRequireScope(trx, N(testapi));
+   transactionAddMessage(trx, msg);
+   transactionSend(trx);
+   return WASM_TEST_PASS;
+}
+
+unsigned int test_transaction::send_transaction_empty() {
+   auto trx = transactionCreate();
+   transactionRequireScope(trx, N(testapi));
+   transactionSend(trx);
+   return WASM_TEST_FAIL;
+}
+
 /**
  * cause failure due to too many pending deferred transactions
  */

libraries/chain/wasm_interface.cpp

@@ -290,18 +290,20 @@ DEFINE_INTRINSIC_FUNCTION4(env,messageCreate,messageCreate,i32,i64,code,i64,type
    auto& wasm  = wasm_interface::get();
    auto  mem   = wasm.current_memory;
    
-   EOS_ASSERT( length > 0, tx_unknown_argument,
-      "Attempting to push an empty message" );
+   EOS_ASSERT( length >= 0, tx_unknown_argument,
+      "Pushing a message with a negative length" );
 
    Bytes payload;
-   try {
-      // memoryArrayPtr checks that the entire array of bytes is valid and
-      // within the bounds of the memory segment so that transactions cannot pass
-      // bad values in attempts to read improper memory
-      const char* buffer = memoryArrayPtr<const char>( mem, uint32_t(data), uint32_t(length) );
-      payload.insert(payload.end(), buffer, buffer + length);
-   } catch( const Runtime::Exception& e ) {
-      FC_THROW_EXCEPTION(tx_unknown_argument, "Message data is not a valid memory range");
+   if (length > 0) {
+      try {
+         // memoryArrayPtr checks that the entire array of bytes is valid and
+         // within the bounds of the memory segment so that transactions cannot pass
+         // bad values in attempts to read improper memory
+         const char* buffer = memoryArrayPtr<const char>( mem, uint32_t(data), uint32_t(length) );
+         payload.insert(payload.end(), buffer, buffer + length);
+      } catch( const Runtime::Exception& e ) {
+         FC_THROW_EXCEPTION(tx_unknown_argument, "Message data is not a valid memory range");
+      }
    }
 
    auto& pmsg = wasm.current_apply_context->create_pending_message(Name(code), Name(type), payload);

tests/api_tests/api_tests.cpp

@@ -384,13 +384,18 @@ BOOST_FIXTURE_TEST_CASE(test_all, testing_fixture)
 
       //Test transaction
       BOOST_CHECK_MESSAGE( CALL_TEST_FUNCTION( TEST_METHOD("test_transaction", "send_message"), {}, {}) == WASM_TEST_PASS, "test_transaction::send_message()");
+      BOOST_CHECK_MESSAGE( CALL_TEST_FUNCTION( TEST_METHOD("test_transaction", "send_message_empty"), {}, {}) == WASM_TEST_PASS, "test_transaction::send_message_empty()");
       BOOST_CHECK_EXCEPTION( CALL_TEST_FUNCTION( TEST_METHOD("test_transaction", "send_message_large"), {}, {} ),
          tx_resource_exhausted, is_tx_resource_exhausted );
       BOOST_CHECK_EXCEPTION( CALL_TEST_FUNCTION( TEST_METHOD("test_transaction", "send_message_max"), {}, {} ),
          tx_resource_exhausted, is_tx_resource_exhausted );
       BOOST_CHECK_EXCEPTION( CALL_TEST_FUNCTION( TEST_METHOD("test_transaction", "send_message_recurse"), {}, fc::raw::pack(dummy13) ),
          tx_resource_exhausted, is_tx_resource_exhausted );
+      BOOST_CHECK_EXCEPTION( CALL_TEST_FUNCTION( TEST_METHOD("test_transaction", "send_message_inline_fail"), {}, {} ),
+         fc::assert_exception, is_assert_exception );
       BOOST_CHECK_MESSAGE( CALL_TEST_FUNCTION( TEST_METHOD("test_transaction", "send_transaction"), {}, {}) == WASM_TEST_PASS, "test_transaction::send_message()");
+      BOOST_CHECK_EXCEPTION( CALL_TEST_FUNCTION( TEST_METHOD("test_transaction", "send_transaction_empty"), {}, {} ),
+         tx_unknown_argument, is_tx_unknown_argument );
       BOOST_CHECK_EXCEPTION( CALL_TEST_FUNCTION( TEST_METHOD("test_transaction", "send_transaction_large"), {}, {} ),
          tx_resource_exhausted, is_tx_resource_exhausted );
       BOOST_CHECK_EXCEPTION( CALL_TEST_FUNCTION( TEST_METHOD("test_transaction", "send_transaction_max"), {}, {} ),