fix getindex bug

Author: dlfivefifty

src/linalg/mul.jl

@@ -166,9 +166,12 @@ getindex(M::MatMulMat, kj::CartesianIndex{2}) = M[kj[1], kj[2]]
 # MulArray
 #####
 
+_mul(A) = A
+_mul(A,B,C...) = Mul(A,B,C...)
+
 function getindex(M::Mul, k)
     A,Bs = first(M.factors), tail(M.factors)
-    B = Mul(Bs)
+    B = _mul(Bs...)
     ret = zero(eltype(M))
     for j = rowsupport(A, k)
         ret += A[k,j] * B[j]
@@ -178,7 +181,7 @@ end
 
 function getindex(M::Mul, k, j)
     A,Bs = first(M.factors), tail(M.factors)
-    B = Mul(Bs)
+    B = _mul(Bs...)
     ret = zero(eltype(M))
     @inbounds for ℓ in (rowsupport(A,k) ∩ colsupport(B,j))
         ret += A[k,ℓ] * B[ℓ,j]

test/multests.jl

@@ -672,9 +672,18 @@ import Base.Broadcast: materialize, materialize!
         M = MulArray(A,A)
         @test Matrix(M) ≈ A^2
     end
+
+    @testset "Bug in getindex" begin
+        M = MulArray([1,2,3],Ones(1,20))
+        @test M[1,1] == 1
+        @test M[2,1] == 2
+    end
 end
 
 
+
+
+
 @testset "Add" begin
     @testset "gemv Float64" begin
         for A in (Add(randn(5,5), randn(5,5)),