diff --git a/src/linalg.jl b/src/linalg.jl
index 8dd9cda3..f315300f 100644
--- a/src/linalg.jl
+++ b/src/linalg.jl
@@ -560,7 +560,7 @@ function LinearAlgebra.generic_trimatmul!(C::StridedVecOrMat, uploc, isunitc, tf
     end
     return C
 end
-function LinearAlgebra.generic_trimatmul!(C::StridedVecOrMat, uploc, isunitc, _, xA::AdjOrTrans{<:Any,<:SparseMatrixCSCUnion}, B::AbstractVecOrMat)
+function LinearAlgebra.generic_trimatmul!(C::StridedVecOrMat, uploc, isunitc, ::Function, xA::AdjOrTrans{<:Any,<:SparseMatrixCSCUnion}, B::AbstractVecOrMat)
     A = parent(xA)
     nrowC = size(C, 1)
     ncol = checksquare(A)
diff --git a/src/sparsematrix.jl b/src/sparsematrix.jl
index 1703c870..165a7046 100644
--- a/src/sparsematrix.jl
+++ b/src/sparsematrix.jl
@@ -3179,7 +3179,8 @@ function Base.fill!(V::SubArray{Tv, <:Any, <:AbstractSparseMatrixCSC{Tv}, <:Tupl
     else
         _spsetnz_setindex!(A, convert(Tv, x), I, J)
     end
-    return _checkbuffers(A)
+    _checkbuffers(A)
+    V
 end
 """
 Helper method for immediately preceding fill! method. For all (i,j) such that i in I and
@@ -3207,7 +3208,7 @@ function _spsetz_setindex!(A::AbstractSparseMatrixCSC,
                 kI > lengthI && break
                 entrykIrow = I[kI]
             else # entrykArow == entrykIrow
-                nonzeros(A)[kA] = 0
+                nonzeros(A)[kA] = zero(eltype(A))
                 kA += 1
                 kI += 1
                 (kA > coljAlastk || kI > lengthI) && break
diff --git a/test/ambiguous.jl b/test/ambiguous.jl
index c1372145..0b32e472 100644
--- a/test/ambiguous.jl
+++ b/test/ambiguous.jl
@@ -27,13 +27,13 @@ using Test, LinearAlgebra, SparseArrays, Aqua
 
 @testset "code quality" begin
     @testset "Method ambiguity" begin
-        # Aqua.test_ambiguities([SparseArrays, Base, Core])
+        Aqua.test_ambiguities([SparseArrays, Base, Core])
     end
     @testset "Unbound type parameters" begin
         @test_broken Aqua.detect_unbound_args_recursively(SparseArrays) == []
     end
     @testset "Undefined exports" begin
-        Aqua.test_undefined_exports(SparseArrays) == []
+        Aqua.test_undefined_exports(SparseArrays)
     end
     @testset "Compare Project.toml and test/Project.toml" begin
         Aqua.test_project_extras(SparseArrays)
@@ -53,13 +53,9 @@ using Test, LinearAlgebra, SparseArrays, Aqua
 end
 
 let ambig = detect_ambiguities(SparseArrays; recursive=true)
-    @test_broken isempty(ambig)
+    @test isempty(ambig)
     ambig = Set{Any}(((m1.sig, m2.sig) for (m1, m2) in ambig))
     expect = []
-    push!(expect, (Tuple{typeof(LinearAlgebra.generic_trimatmul!), AbstractVecOrMat, Any, Any, Function, AbstractMatrix, AbstractVecOrMat},
-                   Tuple{typeof(LinearAlgebra.generic_trimatmul!), StridedVecOrMat, Any, Any, Any, Union{Adjoint{var"#s388", var"#s387"}, Transpose{var"#s388", var"#s387"}} where {var"#s388", var"#s387"<:(Union{SparseArrays.AbstractSparseMatrixCSC{Tv, Ti}, SubArray{Tv, 2, <:SparseArrays.AbstractSparseMatrixCSC{Tv, Ti}, Tuple{Base.Slice{Base.OneTo{Int}}, I}} where I<:AbstractUnitRange} where {Tv, Ti})}, AbstractVecOrMat}))
-    push!(expect, (Tuple{typeof(LinearAlgebra.generic_trimatmul!), AbstractVecOrMat, Any, Any, Function, Union{Adjoint{T, S}, Transpose{T, S}} where {T, S}, AbstractVecOrMat},
-                   Tuple{typeof(LinearAlgebra.generic_trimatmul!), StridedVecOrMat, Any, Any, Any, Union{Adjoint{var"#s388", var"#s387"}, Transpose{var"#s388", var"#s387"}} where {var"#s388", var"#s387"<:(Union{SparseArrays.AbstractSparseMatrixCSC{Tv, Ti}, SubArray{Tv, 2, <:SparseArrays.AbstractSparseMatrixCSC{Tv, Ti}, Tuple{Base.Slice{Base.OneTo{Int}}, I}} where I<:AbstractUnitRange} where {Tv, Ti})}, AbstractVecOrMat}))
     good = true
     while !isempty(ambig)
         sigs = pop!(ambig)
diff --git a/test/linalg.jl b/test/linalg.jl
index c1f5880f..7b8aba54 100644
--- a/test/linalg.jl
+++ b/test/linalg.jl
@@ -162,6 +162,18 @@ begin
         vMAW = tr(wr(view(MA, :, 1:n)))
         @test vAW * B ≈ vMAW * B
     end
+    a = sprand(rng, ComplexF64, n, n, 0.01)
+    ma = Matrix(a)
+    @testset "triangular multiply with conjugate matrices" for tr in (x -> adjoint(transpose(x)), x -> transpose(adjoint(x))),
+        wr in (UpperTriangular, LowerTriangular, UnitUpperTriangular, UnitLowerTriangular)
+        AW = tr(wr(a))
+        MAW = tr(wr(ma))
+        @test AW * B ≈ MAW * B
+        # and for SparseMatrixCSCView - a view of all rows and unit range of cols
+        vAW = tr(wr(view(a, :, 1:n)))
+        vMAW = tr(wr(view(ma, :, 1:n)))
+        @test vAW * B ≈ vMAW * B
+    end
     A = A - Diagonal(diag(A)) + 2I # avoid rounding errors by division
     MA = Matrix(A)
     @testset "triangular solver for $tr($wr)" for tr in (identity, adjoint, transpose),
diff --git a/test/sparsematrix_constructors_indexing.jl b/test/sparsematrix_constructors_indexing.jl
index 5aad5628..0278c4be 100644
--- a/test/sparsematrix_constructors_indexing.jl
+++ b/test/sparsematrix_constructors_indexing.jl
@@ -342,7 +342,7 @@ end
     A = rand(5,5)
     A´ = similar(A)
     Ac = copyto!(A, B)
-    @test Ac === A 
+    @test Ac === A
     @test A == copyto!(A´, Matrix(B))
     # Test copyto!(dense, Rdest, sparse, Rsrc)
     A = rand(5,5)
@@ -1363,7 +1363,9 @@ end
     a = sprand(10, 10, 0.2)
     b = copy(a)
     sa = view(a, 1:10, 2:3)
-    fill!(sa, 0.0)
+    sa_filled = fill!(sa, 0.0)
+    # `fill!` should return the sub array instead of its parent.
+    @test sa_filled === sa
     b[1:10, 2:3] .= 0.0
     @test a == b
     A = sparse([1], [1], [Vector{Float64}(undef, 3)], 3, 3)
@@ -1375,6 +1377,17 @@ end
         B[1, jj] = [4.0, 5.0, 6.0]
     end
     @test A == B
+
+    # https://github.com/JuliaSparse/SparseArrays.jl/pull/433
+    struct Foo
+       x::Int
+    end
+    Base.zero(::Type{Foo}) = Foo(0)
+    Base.zero(::Foo) = zero(Foo)
+    C = sparse([1], [1], [Foo(3)], 3, 3)
+    sC = view(C, 1:1, 1:2)
+    fill!(sC, zero(Foo))
+    @test C[1:1, 1:2] == zeros(Foo, 1, 2)
 end
 
 using Base: swaprows!, swapcols!