check for typemin(T) in denominator of rational (JuliaLang#32572)

halleysfifthinc · Dec 17, 2019 · fdcaa06 · fdcaa06
1 parent 56d75f7
commit fdcaa06
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Showing 2 changed files with 14 additions and 4 deletions.
diff --git a/base/rational.jl b/base/rational.jl
@@ -11,12 +11,18 @@ struct Rational{T<:Integer} <: Real
  den::T
 
  function Rational{T}(num::Integer, den::Integer) where T<:Integer
- num == den == zero(T) && __throw_rational_argerror(T)
- num2, den2 = signbit(den) ? divgcd(-num, -den) : divgcd(num, den)
- new(num2, den2)
+ num == den == zero(T) && __throw_rational_argerror_zero(T)
+ num2, den2 = divgcd(num, den)
+ if T<:Signed && signbit(den2)
+ den2 = -den2
+ signbit(den2) && __throw_rational_argerror_typemin(T)
+ num2 = -num2
+ end
+ return new(num2, den2)
  end
 end
-@noinline __throw_rational_argerror(T) = throw(ArgumentError("invalid rational: zero($T)//zero($T)"))
+@noinline __throw_rational_argerror_zero(T) = throw(ArgumentError("invalid rational: zero($T)//zero($T)"))
+@noinline __throw_rational_argerror_typemin(T) = throw(ArgumentError("invalid rational: denominator can't be typemin($T)"))
 
 Rational(n::T, d::T) where {T<:Integer} = Rational{T}(n,d)
 Rational(n::Integer, d::Integer) = Rational(promote(n,d)...)

diff --git a/test/rational.jl b/test/rational.jl
@@ -32,6 +32,10 @@ using Test
  @test_throws ArgumentError rationalize(Int, big(3.0), -1.)
  # issue 26823
  @test_throws InexactError rationalize(Int, NaN)
+ # issue 32569
+ @test_throws ArgumentError 1 // typemin(Int)
+ @test -2 // typemin(Int) == -1 // (typemin(Int) >> 1)
+ @test 2 // typemin(Int) == 1 // (typemin(Int) >> 1)
 
  for a = -5:5, b = -5:5
  if a == b == 0; continue; end