From 01a01ef063c6d6e7d81cd663e85cc4af034585f1 Mon Sep 17 00:00:00 2001
From: Denis Barucic <barucden@fel.cvut.cz>
Date: Mon, 21 Mar 2022 13:06:29 +0100
Subject: [PATCH] MPFR: Fix `round(Integer, big(Inf))` (#44676)

It also fixes `round(Integer, big(NaN))`.

Solves #44662

(cherry picked from commit ecf3558c94898ddd4272b319d3405cf7256c6db7)
---
 base/mpfr.jl | 9 ++++++++-
 test/mpfr.jl | 4 ++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/base/mpfr.jl b/base/mpfr.jl
index e85f281619ac0..60f59cdb0af7e 100644
--- a/base/mpfr.jl
+++ b/base/mpfr.jl
@@ -294,7 +294,14 @@ function round(::Type{T}, x::BigFloat, r::Union{RoundingMode, MPFRRoundingMode})
     end
     return unsafe_trunc(T, res)
 end
-round(::Type{BigInt}, x::BigFloat, r::Union{RoundingMode, MPFRRoundingMode}) = _unchecked_cast(BigInt, x, r)
+
+function round(::Type{BigInt}, x::BigFloat, r::Union{RoundingMode, MPFRRoundingMode})
+    clear_flags()
+    res = _unchecked_cast(BigInt, x, r)
+    had_range_exception() && throw(InexactError(:round, BigInt, x))
+    return res
+end
+
 round(::Type{T}, x::BigFloat, r::RoundingMode) where T<:Union{Signed, Unsigned} =
     invoke(round, Tuple{Type{<:Union{Signed, Unsigned}}, BigFloat, Union{RoundingMode, MPFRRoundingMode}}, T, x, r)
 round(::Type{BigInt}, x::BigFloat, r::RoundingMode) =
diff --git a/test/mpfr.jl b/test/mpfr.jl
index a1039a7c5a810..1a0a0041bf94e 100644
--- a/test/mpfr.jl
+++ b/test/mpfr.jl
@@ -653,6 +653,10 @@ end
     @test typeof(round(Int64, x)) == Int64 && round(Int64, x) == 42
     @test typeof(round(Int, x)) == Int && round(Int, x) == 42
     @test typeof(round(UInt, x)) == UInt && round(UInt, x) == 0x2a
+
+    # Issue #44662
+    @test_throws InexactError round(Integer, big(Inf))
+    @test_throws InexactError round(Integer, big(NaN))
 end
 @testset "string representation" begin
     str = "1.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000012"