Fix sparse right multiplication of Symmetric and Hermitian matrices (#21431). (#21432)

(cherry picked from commit 8a3b6c1)

Author: pkofod

base/sparse/cholmod.jl

@@ -1622,4 +1622,11 @@ end
 (*){Ti}(A::Hermitian{Complex{Float64},SparseMatrixCSC{Complex{Float64},Ti}}, B::SparseVecOrMat{Complex{Float64},Ti}) = sparse(Sparse(A)*Sparse(B))
 (*){Ti}(A::Hermitian{Float64,SparseMatrixCSC{Float64,Ti}}, B::SparseVecOrMat{Float64,Ti}) = sparse(Sparse(A)*Sparse(B))
 
+(*){Ti}(A::SparseVecOrMat{Float64,Ti},
+    B::Symmetric{Float64,SparseMatrixCSC{Float64,Ti}}) = sparse(Sparse(A)*Sparse(B))
+(*){Ti}(A::SparseVecOrMat{Complex{Float64},Ti},
+    B::Hermitian{Complex{Float64},SparseMatrixCSC{Complex{Float64},Ti}}) = sparse(Sparse(A)*Sparse(B))
+(*){Ti}(A::SparseVecOrMat{Float64,Ti},
+    B::Hermitian{Float64,SparseMatrixCSC{Float64,Ti}}) = sparse(Sparse(A)*Sparse(B))
+
 end #module

test/sparsedir/cholmod.jl

@@ -696,3 +696,11 @@ for A in (SparseMatrixCSC(2, 2, [1, 2], CHOLMOD.SuiteSparse_long[], Float64[]),
     @test_throws ArgumentError CHOLMOD.Sparse(size(A)..., A.colptr - 1, A.rowval - 1, A.nzval)
     @test_throws ArgumentError CHOLMOD.Sparse(A)
 end
+
+# sparse right multiplication of Symmetric and Hermitian matrices #21431
+@test issparse(speye(2)*speye(2)*speye(2))
+for T in (Symmetric, Hermitian)
+    @test issparse(speye(2)*T(speye(2))*speye(2))
+    @test issparse(speye(2)*(T(speye(2))*speye(2)))
+    @test issparse((speye(2)*T(speye(2)))*speye(2))
+end