Check sizes in 3-arg diagonal (dot-)product (#47114)

(cherry picked from commit 25e3809)
JuliaLang · Dec 21, 2022 · 43a5056 · 43a5056
1 parent 9895223
commit 43a5056
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diff --git a/stdlib/LinearAlgebra/src/diagonal.jl b/stdlib/LinearAlgebra/src/diagonal.jl
@@ -699,6 +699,9 @@ end
 dot(A::AbstractMatrix, B::Diagonal) = conj(dot(B, A))
 
 function _mapreduce_prod(f, x, D::Diagonal, y)
+ if !(length(x) == length(D.diag) == length(y))
+ throw(DimensionMismatch("x has length $(length(x)), D has size $(size(D)), and y has $(length(y))"))
+ end
  if isempty(x) && isempty(D) && isempty(y)
  return zero(Base.promote_op(f, eltype(x), eltype(D), eltype(y)))
  else

diff --git a/stdlib/LinearAlgebra/test/diagonal.jl b/stdlib/LinearAlgebra/test/diagonal.jl
@@ -738,10 +738,14 @@ end
  @test s1 == prod(sign, d)
 end
 
-@testset "Empty (#35424)" begin
+@testset "Empty (#35424) & size checks (#47060)" begin
  @test zeros(0)'*Diagonal(zeros(0))*zeros(0) === 0.0
  @test transpose(zeros(0))*Diagonal(zeros(Complex{Int}, 0))*zeros(0) === 0.0 + 0.0im
  @test dot(zeros(Int32, 0), Diagonal(zeros(Int, 0)), zeros(Int16, 0)) === 0
+ @test_throws DimensionMismatch zeros(2)' * Diagonal(zeros(2)) * zeros(3)
+ @test_throws DimensionMismatch zeros(3)' * Diagonal(zeros(2)) * zeros(2)
+ @test_throws DimensionMismatch dot(zeros(2), Diagonal(zeros(2)), zeros(3))
+ @test_throws DimensionMismatch dot(zeros(3), Diagonal(zeros(2)), zeros(2))
 end
 
 @testset "Inner product" begin