rpc: Accept scientific notation for monetary amounts in JSON

Add a function `ParseFixedPoint` that parses numbers according
to the JSON number specification and returns a 64-bit integer.

Then this in `AmountFromValue`, rather than `ParseMoney`.

Also add lots of tests (thanks to @jonasschnelli for some of them).

Fixes issue #6297.

2 files changed, 87 insertions, 0 deletions

diff --git a/src/test/rpc_tests.cpp b/src/test/rpc_tests.cpp
index 9e99ff6286..25599beafc 100644
--- a/src/test/rpc_tests.cpp
+++ b/src/test/rpc_tests.cpp
@@ -142,6 +142,24 @@ BOOST_AUTO_TEST_CASE(rpc_parse_monetary_values)
     BOOST_CHECK_EQUAL(AmountFromValue(ValueFromString("1.00000000")), 100000000LL);
     BOOST_CHECK_EQUAL(AmountFromValue(ValueFromString("20999999.9999999")), 2099999999999990LL);
     BOOST_CHECK_EQUAL(AmountFromValue(ValueFromString("20999999.99999999")), 2099999999999999LL);
+
+    BOOST_CHECK_EQUAL(AmountFromValue(ValueFromString("1e-8")), COIN/100000000);
+    BOOST_CHECK_EQUAL(AmountFromValue(ValueFromString("0.1e-7")), COIN/100000000);
+    BOOST_CHECK_EQUAL(AmountFromValue(ValueFromString("0.01e-6")), COIN/100000000);
+    BOOST_CHECK_EQUAL(AmountFromValue(ValueFromString("0.0000000000000000000000000000000000000000000000000000000000000000000000000001e+68")), COIN/100000000);
+    BOOST_CHECK_EQUAL(AmountFromValue(ValueFromString("10000000000000000000000000000000000000000000000000000000000000000e-64")), COIN);
+    BOOST_CHECK_EQUAL(AmountFromValue(ValueFromString("0.000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000e64")), COIN);
+
+    BOOST_CHECK_THROW(AmountFromValue(ValueFromString("1e-9")), UniValue); //should fail
+    BOOST_CHECK_THROW(AmountFromValue(ValueFromString("0.000000019")), UniValue); //should fail
+    BOOST_CHECK_EQUAL(AmountFromValue(ValueFromString("0.00000001000000")), 1LL); //should pass, cut trailing 0
+    BOOST_CHECK_THROW(AmountFromValue(ValueFromString("19e-9")), UniValue); //should fail
+    BOOST_CHECK_EQUAL(AmountFromValue(ValueFromString("0.19e-6")), 19); //should pass, leading 0 is present
+
+    BOOST_CHECK_THROW(AmountFromValue(ValueFromString("92233720368.54775808")), UniValue); //overflow error
+    BOOST_CHECK_THROW(AmountFromValue(ValueFromString("1e+11")), UniValue); //overflow error
+    BOOST_CHECK_THROW(AmountFromValue(ValueFromString("1e11")), UniValue); //overflow error signless
+    BOOST_CHECK_THROW(AmountFromValue(ValueFromString("93e+9")), UniValue); //overflow error
 }
 
 BOOST_AUTO_TEST_CASE(json_parse_errors)
@@ -151,6 +169,9 @@ BOOST_AUTO_TEST_CASE(json_parse_errors)
     // Valid, with leading or trailing whitespace
     BOOST_CHECK_EQUAL(ParseNonRFCJSONValue(" 1.0").get_real(), 1.0);
     BOOST_CHECK_EQUAL(ParseNonRFCJSONValue("1.0 ").get_real(), 1.0);
+
+    BOOST_CHECK_THROW(AmountFromValue(ParseNonRFCJSONValue(".19e-6")), std::runtime_error); //should fail, missing leading 0, therefore invalid JSON
+    BOOST_CHECK_EQUAL(AmountFromValue(ParseNonRFCJSONValue("0.00000000000000000000000000000000000001e+30 ")), 1);
     // Invalid, initial garbage
     BOOST_CHECK_THROW(ParseNonRFCJSONValue("[1.0"), std::runtime_error);
     BOOST_CHECK_THROW(ParseNonRFCJSONValue("a1.0"), std::runtime_error);
diff --git a/src/test/util_tests.cpp b/src/test/util_tests.cpp
index 5cb5894251..e956cc5b90 100644
--- a/src/test/util_tests.cpp
+++ b/src/test/util_tests.cpp
@@ -418,4 +418,70 @@ BOOST_AUTO_TEST_CASE(test_FormatSubVersion)
     BOOST_CHECK_EQUAL(FormatSubVersion("Test", 99900, comments),std::string("/Test:0.9.99(comment1)/"));
     BOOST_CHECK_EQUAL(FormatSubVersion("Test", 99900, comments2),std::string("/Test:0.9.99(comment1; comment2)/"));
 }
+
+BOOST_AUTO_TEST_CASE(test_ParseFixedPoint)
+{
+    int64_t amount = 0;
+    BOOST_CHECK(ParseFixedPoint("0", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, 0LL);
+    BOOST_CHECK(ParseFixedPoint("1", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, 100000000LL);
+    BOOST_CHECK(ParseFixedPoint("0.0", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, 0LL);
+    BOOST_CHECK(ParseFixedPoint("-0.1", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, -10000000LL);
+    BOOST_CHECK(ParseFixedPoint("1.1", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, 110000000LL);
+    BOOST_CHECK(ParseFixedPoint("1.10000000000000000", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, 110000000LL);
+    BOOST_CHECK(ParseFixedPoint("1.1e1", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, 1100000000LL);
+    BOOST_CHECK(ParseFixedPoint("1.1e-1", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, 11000000LL);
+    BOOST_CHECK(ParseFixedPoint("1000", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, 100000000000LL);
+    BOOST_CHECK(ParseFixedPoint("-1000", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, -100000000000LL);
+    BOOST_CHECK(ParseFixedPoint("0.00000001", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, 1LL);
+    BOOST_CHECK(ParseFixedPoint("0.0000000100000000", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, 1LL);
+    BOOST_CHECK(ParseFixedPoint("-0.00000001", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, -1LL);
+    BOOST_CHECK(ParseFixedPoint("1000000000.00000001", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, 100000000000000001LL);
+    BOOST_CHECK(ParseFixedPoint("9999999999.99999999", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, 999999999999999999LL);
+    BOOST_CHECK(ParseFixedPoint("-9999999999.99999999", 8, &amount));
+    BOOST_CHECK_EQUAL(amount, -999999999999999999LL);
+
+    BOOST_CHECK(!ParseFixedPoint("", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("-", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("a-1000", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("-a1000", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("-1000a", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("-01000", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("00.1", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint(".1", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("--0.1", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("0.000000001", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("-0.000000001", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("0.00000001000000001", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("-10000000000.00000000", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("10000000000.00000000", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("-10000000000.00000001", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("10000000000.00000001", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("-10000000000.00000009", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("10000000000.00000009", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("-99999999999.99999999", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("99999909999.09999999", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("92233720368.54775807", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("92233720368.54775808", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("-92233720368.54775808", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("-92233720368.54775809", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("1.1e", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("1.1e-", 8, &amount));
+    BOOST_CHECK(!ParseFixedPoint("1.", 8, &amount));
+}
+
 BOOST_AUTO_TEST_SUITE_END()