Remove diagonal changes

Author: jishnub

src/dense.jl

@@ -124,17 +124,6 @@ haszero(::Type) = false
 haszero(::Type{T}) where {T<:Number} = isconcretetype(T)
 haszero(::Type{Union{Missing,T}}) where {T<:Number} = haszero(T)
 @propagate_inbounds _zero(M::AbstractArray{T}, inds...) where {T} = haszero(T) ? zero(T) : zero(M[inds...])
-function zero!(M::AbstractArray{T}) where {T}
-    if haszero(T)
-        fill!(M, zero(T))
-    else
-        for i in eachindex(M)
-            v = @inbounds M[i]
-            z = zero(v)
-            @inbounds M[i] = z
-        end
-    end
-end
 
 """
     triu!(M, k::Integer)

src/diagonal.jl

@@ -279,7 +279,7 @@ function triu!(D::Diagonal{T}, k::Integer=0) where T
         throw(ArgumentError(string("the requested diagonal, $k, must be at least ",
             "$(-n + 1) and at most $(n + 1) in an $n-by-$n matrix")))
     elseif k > 0
-        zero!(D.diag)
+        fill!(D.diag, zero(T))
     end
     return D
 end
@@ -290,7 +290,7 @@ function tril!(D::Diagonal{T}, k::Integer=0) where T
         throw(ArgumentError(LazyString(lazy"the requested diagonal, $k, must be at least ",
             lazy"$(-n - 1) and at most $(n - 1) in an $n-by-$n matrix")))
     elseif k < 0
-        zero!(D.diag)
+        fill!(D.diag, zero(T))
     end
     return D
 end

test/dense.jl

@@ -1408,4 +1408,13 @@ end
     @test 2^A == 2^Matrix(A)
 end
 
+@testset "triu/tril for block matrices" begin
+    O = ones(2,2)
+    Z = zero(O)
+    M = fill(O, 3, 3)
+    res = fill(Z, size(M))
+    res[1,2] = res[1,3] = res[2,3] = O
+    @test triu(GenericArray(M),1) == res
+end
+
 end # module TestDense

test/diagonal.jl

@@ -819,13 +819,6 @@ end
         @test all(x -> size(x) == (2,2), D)
         @test D == D1 * D2
     end
-
-    @testset "triu/tril" begin
-        D = Diagonal(fill(ones(2,2), 3))
-        M = Matrix{eltype(D)}(D)
-        @test triu(D,1) == triu(M,1)
-        @test tril(D,-1) == tril(M,-1)
-    end
 end
 
 @testset "Eigensystem for block diagonal (issue #30681)" begin