From 8a5a6eba7bd75d6bb8a99796055ce6ce8992b74f Mon Sep 17 00:00:00 2001 From: Tero Kinnunen Date: Mon, 8 Nov 2021 09:46:03 +0200 Subject: [PATCH] Parse large floats as infinity (#1349) Return 1.9.1 functionality where values too large to fit in double are converted to positive or negative infinity. Commit 645cd04 changed functionality so that large floats cause parse error, while version 1.9.1 accepted them as infinite. This is problematic because writer outputs infinity values as `1e+9999`, which could no longer be parsed back. Fixed also legacy Reader even though it did not parse large values even before breaking change, due to problematic output/parse asymmetry. `>>` operator sets value to numeric_limits::max/lowest value if representation is too large to fit to double. [1][2] In macos value appears to be parsed to infinity. > | value in *val* | description | > |--------------------------|-------------| > | numeric_limits::max() | The sequence represents a value too large for the type of val | > | numeric_limits::lowest() | The sequence represents a value too large negative for the type of val | [1] https://www.cplusplus.com/reference/istream/istream/operator%3E%3E/ [2] https://www.cplusplus.com/reference/locale/num_get/get/ Signed-off-by: Tero Kinnunen --- src/lib_json/json_reader.cpp | 18 +++++++++++++++--- test/data/legacy_test_real_13.expected | 3 +++ test/data/legacy_test_real_13.json | 1 + 3 files changed, 19 insertions(+), 3 deletions(-) create mode 100644 test/data/legacy_test_real_13.expected create mode 100644 test/data/legacy_test_real_13.json diff --git a/src/lib_json/json_reader.cpp b/src/lib_json/json_reader.cpp index a6a3f4e30..896bf1b91 100644 --- a/src/lib_json/json_reader.cpp +++ b/src/lib_json/json_reader.cpp @@ -12,6 +12,7 @@ #endif // if !defined(JSON_IS_AMALGAMATION) #include #include +#include #include #include #include @@ -600,9 +601,15 @@ bool Reader::decodeDouble(Token& token, Value& decoded) { double value = 0; String buffer(token.start_, token.end_); IStringStream is(buffer); - if (!(is >> value)) - return addError( + if (!(is >> value)) { + if (value == std::numeric_limits::max()) + value = std::numeric_limits::infinity(); + else if (value == std::numeric_limits::lowest()) + value = -std::numeric_limits::infinity(); + else if (!std::isinf(value)) + return addError( "'" + String(token.start_, token.end_) + "' is not a number.", token); + } decoded = value; return true; } @@ -1647,7 +1654,12 @@ bool OurReader::decodeDouble(Token& token, Value& decoded) { const String buffer(token.start_, token.end_); IStringStream is(buffer); if (!(is >> value)) { - return addError( + if (value == std::numeric_limits::max()) + value = std::numeric_limits::infinity(); + else if (value == std::numeric_limits::lowest()) + value = -std::numeric_limits::infinity(); + else if (!std::isinf(value)) + return addError( "'" + String(token.start_, token.end_) + "' is not a number.", token); } decoded = value; diff --git a/test/data/legacy_test_real_13.expected b/test/data/legacy_test_real_13.expected new file mode 100644 index 000000000..8d3f03faa --- /dev/null +++ b/test/data/legacy_test_real_13.expected @@ -0,0 +1,3 @@ +.=[] +.[0]=-inf +.[1]=inf diff --git a/test/data/legacy_test_real_13.json b/test/data/legacy_test_real_13.json new file mode 100644 index 000000000..287258a81 --- /dev/null +++ b/test/data/legacy_test_real_13.json @@ -0,0 +1 @@ +[-1e+9999, 1e+9999]