Merge pull request #2735 from EOSIO/decimals

Fix for #2322 - eosio.token transfer succeeds or fails depending on decimal digits count

contracts/eosio.token/eosio.token.cpp

@@ -78,6 +78,9 @@ void token::transfer( account_name from,
     eosio_assert( quantity.is_valid(), "invalid quantity" );
     eosio_assert( quantity.amount > 0, "must transfer positive quantity" );
 
+    if ( quantity.symbol.precision() != st.supply.symbol.precision() )
+       quantity.adjust_precision( st.supply.symbol );
+
     sub_balance( from, quantity, st );
     add_balance( to, quantity, st, from );
 }

contracts/eosiolib/asset.hpp

@@ -251,6 +251,18 @@ namespace eosio {
          symbol.print(false);
       }
 
+      void adjust_precision(const symbol_type& ref_sym) {
+         eosio_assert(this->symbol.name() == ref_sym.name(), "comparison of symbols with different names is not allowed");
+         if (this->symbol.precision() == ref_sym.precision())
+            return;
+         eosio_assert(ref_sym.precision() >= this->symbol.precision(), "asset symbol has higher precision than expected");
+         for (uint8_t i = 0; i < ref_sym.precision() - this->symbol.precision(); ++i) {
+            printi(amount);
+            this->amount *= 10;
+         }
+         this->symbol.value = ref_sym.value;
+      }
+
       EOSLIB_SERIALIZE( asset, (amount)(symbol) )
    };
 

unittests/currency_tests.cpp

@@ -52,7 +52,17 @@ class currency_tester : public TESTER {
          return get_currency_balance(N(eosio.token), symbol(SY(4,CUR)), account);
       }
 
-
+      auto transfer(const account_name& from, const account_name& to, const std::string& quantity, const std::string& memo = "") {
+         auto trace = push_action(from, N(transfer), mutable_variant_object()
+                                  ("from",     from)
+                                  ("to",       to)
+                                  ("quantity", quantity)
+                                  ("memo",     memo)
+                                  );
+         produce_block();
+         return trace;
+      }
+      
       currency_tester()
       :TESTER(),abi_ser(json::from_string(eosio_token_abi).as<abi_def>())
       {
@@ -523,4 +533,52 @@ BOOST_FIXTURE_TEST_CASE( test_deferred_failure, currency_tester ) try {
 
 } FC_LOG_AND_RETHROW() /// test_currency
 
+BOOST_FIXTURE_TEST_CASE( test_input_quantity, currency_tester ) try {
+
+   produce_blocks(2);
+   
+   create_accounts( {N(alice), N(bob), N(carl)} );
+
+   // transfer to alice using right precision
+   {
+      auto trace = transfer(eosio_token, N(alice), "100.0000 CUR");
+
+      BOOST_CHECK_EQUAL(true, chain_has_transaction(trace->id));
+      BOOST_CHECK_EQUAL(asset::from_string( "100.0000 CUR"), get_balance(N(alice)));
+      BOOST_CHECK_EQUAL(1000000, get_balance(N(alice)).amount);
+   }
+
+   // transfer from alice to bob using no decimal point
+   {
+      auto trace = transfer(N(alice), N(bob), "13 CUR");
+
+      BOOST_CHECK_EQUAL(true, chain_has_transaction(trace->id));
+      BOOST_CHECK_EQUAL(asset::from_string("13.0000 CUR"), get_balance(N(bob)));
+      BOOST_CHECK_EQUAL(asset::from_string("87.0000 CUR"), get_balance(N(alice)));
+   }
+
+   // transfer from bob to carl using lower precision
+   {
+      auto trace = transfer(N(bob), N(carl), "2.01 CUR");
+
+      BOOST_CHECK_EQUAL(true, chain_has_transaction(trace->id));
+      BOOST_CHECK_EQUAL(asset::from_string("2.0100 CUR"),  get_balance(N(carl)));
+      BOOST_CHECK_EQUAL(asset::from_string("10.9900 CUR"), get_balance(N(bob)));
+   }
+
+   // transfer using higher precision fails
+   {
+      BOOST_REQUIRE_EXCEPTION(transfer(N(alice), N(carl), "5.34567 CUR"), assert_exception,
+                              [](const assert_exception& e) -> bool {
+                                 return e.get_log().at(0).get_message() == "condition: assertion failed: asset symbol has higher precision than expected"; 
+                              });
+   }
+
+   // transfer using different symbol name fails
+   {
+      BOOST_REQUIRE_THROW(transfer(N(alice), N(carl), "20.50 USD"), assert_exception);
+   }
+
+} FC_LOG_AND_RETHROW() /// test_currency
+
 BOOST_AUTO_TEST_SUITE_END()