fix rankcorr size overflow

src/AggregateFunctions/AggregateFunctionRankCorrelation.h

@@ -32,7 +32,7 @@ struct RankCorrelationData : public StatisticalSample<Float64, Float64>
         std::tie(ranks_y, std::ignore) = computeRanksAndTieCorrection(this->y);
 
         /// Sizes can be non-equal due to skipped NaNs.
-        const auto size = std::min(this->size_x, this->size_y);
+        const Float32 size = static_cast<Float32>(std::min(this->size_x, this->size_y));
 
         /// Count d^2 sum
         Float64 answer = 0;

tests/queries/0_stateless/02347_rank_corr_size_overflow.reference

@@ -0,0 +1 @@
+-1

tests/queries/0_stateless/02347_rank_corr_size_overflow.sql

@@ -0,0 +1 @@
+SELECT round(rankCorr(number, -number)) FROM numbers(5000000);