From 62563b8116c8eaed89721fe7d205b2095a3f06c0 Mon Sep 17 00:00:00 2001
From: garrettthomaskth <garrettt@kth.se>
Date: Mon, 29 Aug 2016 14:23:47 +0200
Subject: [PATCH] lufact for sparse matrix pivot option error (#18246)

* lufact for sparse matrix pivot option error

base/sparse/umfpack.jl includes the following method definition for lufact

`lufact(A::SparseMatrixCSC, pivot::Type{Val{false}}) = lufact(A)`

This should likely be

`lufact(A::SparseMatrixCSC, pivot::Type{Val{true}}) = lufact(A)`

because in lufact pivoting is on by default.

The error is shown in the following example

```
A = speye(4)
A[1:2,1:2] = [-.01 -200; 200 .001]
F = lufact(A,Val{false})
F[:p]
```
which returns
```
julia> F[:q]
4-element Array{Int64,1}:
 3
 4
 1
 2
```
However it should return
```
julia> F[:q]
4-element Array{Int64,1}:
1
2
3
4
```
because pivoting was turned off.

* Added test for #18246 and #18244

* 4 space indent

oops my bad

* remove unnecessary lufact method

* update test for removed lufact method definition

(cherry picked from commit 68d3d329ce369830433364d275c308a4dbc1bd46)
---
 base/sparse/umfpack.jl    |  1 -
 test/sparsedir/umfpack.jl | 10 +++++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/base/sparse/umfpack.jl b/base/sparse/umfpack.jl
index 3b426bb9f234d..25f4b9935a7d1 100644
--- a/base/sparse/umfpack.jl
+++ b/base/sparse/umfpack.jl
@@ -157,7 +157,6 @@ lufact{T<:AbstractFloat}(A::Union{SparseMatrixCSC{T},SparseMatrixCSC{Complex{T}}
     "sparse floating point LU using UMFPACK or lufact(full(A)) for generic ",
     "dense LU.")))
 lufact(A::SparseMatrixCSC) = lufact(float(A))
-lufact(A::SparseMatrixCSC, pivot::Type{Val{false}}) = lufact(A)
 
 
 size(F::UmfpackLU) = (F.m, F.n)
diff --git a/test/sparsedir/umfpack.jl b/test/sparsedir/umfpack.jl
index 6db636a20353e..6ce7877e58011 100644
--- a/test/sparsedir/umfpack.jl
+++ b/test/sparsedir/umfpack.jl
@@ -136,4 +136,12 @@ let
     @test_throws ArgumentError Base.SparseArrays.UMFPACK.solve!(a, lufact(speye(5,5)), a, Base.SparseArrays.UMFPACK.UMFPACK_A)
     aa = complex(a)
     @test_throws ArgumentError Base.SparseArrays.UMFPACK.solve!(aa, lufact(complex(speye(5,5))), aa, Base.SparseArrays.UMFPACK.UMFPACK_A)
-end
\ No newline at end of file
+end
+
+#18246,18244-lufact sparse pivot
+let
+    A = speye(4)
+    A[1:2,1:2] = [-.01 -200; 200 .001]
+    F = lufact(A)
+    @test F[:p] == [3 ; 4 ; 2 ; 1]
+end