From 8093d8c47c25c38dcc2f9dba3e2eb680d8a1d7a5 Mon Sep 17 00:00:00 2001 From: YaalLek <140312422+YaalLek@users.noreply.github.com> Date: Wed, 22 Nov 2023 17:33:24 +0200 Subject: [PATCH] json_value.cpp bug in the edges of uint/int Fixing bug of sending a number that is a bit bigger than max it returns 0: https://stackoverflow.com/questions/77261400/jsoncpp-do-not-protect-from-uint64-overflow-and-have-weird-behavior/77261716#77261716 --- src/lib_json/json_value.cpp | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/src/lib_json/json_value.cpp b/src/lib_json/json_value.cpp index 7b83497..4ad67c8 100644 --- a/src/lib_json/json_value.cpp +++ b/src/lib_json/json_value.cpp @@ -88,7 +88,7 @@ static inline bool InRange(double d, T min, U max) { // The casts can lose precision, but we are looking only for // an approximate range. Might fail on edge cases though. ~cdunn return d >= static_cast(min) && d <= static_cast(max) && - !(static_cast(d) != min || d == min); + !(static_cast(d) == min && d != static_cast(min)); } #else // if !defined(JSON_USE_INT64_DOUBLE_CONVERSION) static inline double integerToDouble(Json::UInt64 value) { @@ -103,7 +103,7 @@ template static inline double integerToDouble(T value) { template static inline bool InRange(double d, T min, U max) { return d >= integerToDouble(min) && d <= integerToDouble(max) && - !(static_cast(d) == min || d != integerToDouble(min)); + !(static_cast(d) == min && d != integerToDouble(min)); } #endif // if !defined(JSON_USE_INT64_DOUBLE_CONVERSION) @@ -707,6 +707,10 @@ Value::Int64 Value::asInt64() const { JSON_ASSERT_MESSAGE(isInt64(), "LargestUInt out of Int64 range"); return Int64(value_.uint_); case realValue: + // If the double value is in proximity to minInt64, it will be rounded to minInt64. + // The correct value in this scenario is indeterminable + JSON_ASSERT_MESSAGE(value_.real_ != minInt64, + "Double value is minInt64, precise value cannot be determined"); JSON_ASSERT_MESSAGE(InRange(value_.real_, minInt64, maxInt64), "double out of Int64 range"); return Int64(value_.real_); @@ -1310,7 +1314,10 @@ bool Value::isInt64() const { // Note that maxInt64 (= 2^63 - 1) is not exactly representable as a // double, so double(maxInt64) will be rounded up to 2^63. Therefore we // require the value to be strictly less than the limit. - return value_.real_ >= double(minInt64) && + // minInt64 is -2^63 which can be represented as a double, but since double values in its proximity are also + // rounded to -2^63, we require the value to be strictly greater than the limit to avoid returning + // 'true' for values that are not in the range + return value_.real_ > double(minInt64) && value_.real_ < double(maxInt64) && IsIntegral(value_.real_); default: break; @@ -1349,7 +1356,10 @@ bool Value::isIntegral() const { // Note that maxUInt64 (= 2^64 - 1) is not exactly representable as a // double, so double(maxUInt64) will be rounded up to 2^64. Therefore we // require the value to be strictly less than the limit. - return value_.real_ >= double(minInt64) && + // minInt64 is -2^63 which can be represented as a double, but since double values in its proximity are also + // rounded to -2^63, we require the value to be strictly greater than the limit to avoid returning + // 'true' for values that are not in the range + return value_.real_ > double(minInt64) && value_.real_ < maxUInt64AsDouble && IsIntegral(value_.real_); #else return value_.real_ >= minInt && value_.real_ <= maxUInt &&