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Makes Types in Squared Dist Calculation Explicit, see #3483.

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This commit is contained in:
Daniel J. Hofmann 2016-12-22 12:56:58 +01:00 committed by Daniel J. H
parent 76de3b6ace
commit 7b11cd3a11
2 changed files with 22 additions and 3 deletions
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11
src/util/coordinate_calculation.cpp
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@ -21,10 +21,15 @@ namespace coordinate_calculation
// Does not project the coordinates! // Does not project the coordinates!
std::uint64_t squaredEuclideanDistance(const Coordinate lhs, const Coordinate rhs) std::uint64_t squaredEuclideanDistance(const Coordinate lhs, const Coordinate rhs)
{ {
const std::uint64_t dx = static_cast<std::int32_t>(lhs.lon - rhs.lon); std::int64_t d_lon = static_cast<std::int32_t>(lhs.lon - rhs.lon);
const std::uint64_t dy = static_cast<std::int32_t>(lhs.lat - rhs.lat); std::int64_t d_lat = static_cast<std::int32_t>(lhs.lat - rhs.lat);
return dx * dx + dy * dy; std::int64_t sq_lon = d_lon * d_lon;
std::int64_t sq_lat = d_lat * d_lat;
std::uint64_t result = static_cast<std::uint64_t>(sq_lon + sq_lat);
return result;
} }
double haversineDistance(const Coordinate coordinate_1, const Coordinate coordinate_2) double haversineDistance(const Coordinate coordinate_1, const Coordinate coordinate_2)

14
unit_tests/util/coordinate_calculation.cpp
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@ -311,4 +311,18 @@ BOOST_AUTO_TEST_CASE(circleCenter)
BOOST_CHECK(!result); BOOST_CHECK(!result);
} }
// For overflow issue #3483, introduced in 68ee4eab61548. Run with -fsanitize=integer.
BOOST_AUTO_TEST_CASE(squaredEuclideanDistance)
{
// Overflow happens when left hand side values are smaller than right hand side values,
// then `lhs - rhs` will be negative but stored in a uint64_t (wraps around).
Coordinate lhs(FloatLongitude{-180}, FloatLatitude{-90});
Coordinate rhs(FloatLongitude{180}, FloatLatitude{90});
const auto result = coordinate_calculation::squaredEuclideanDistance(lhs, rhs);
BOOST_CHECK_EQUAL(result, 162000000000000000ull);
}
BOOST_AUTO_TEST_SUITE_END() BOOST_AUTO_TEST_SUITE_END()