From a85cc64500b07739672c7d1fa8832b17f18a1bf1 Mon Sep 17 00:00:00 2001
From: Paolo Gentili <pgentili@mit.edu>
Date: Sat, 6 Feb 2016 17:26:10 -0500
Subject: [PATCH] fix #14111 dividing sparse vector by constant should give
 sparse vector

---
 base/sparse.jl                 |  2 +-
 base/sparse/sparsevector.jl    |  9 +++++++++
 test/sparsedir/sparsevector.jl | 22 ++++++++++++++++++++++
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/base/sparse.jl b/base/sparse.jl
index e8ae4bf35b61b..edc97f188e829 100644
--- a/base/sparse.jl
+++ b/base/sparse.jl
@@ -6,7 +6,7 @@ using Base: Func, AddFun, OrFun, ConjFun, IdFun
 using Base.Sort: Forward
 using Base.LinAlg: AbstractTriangular, PosDefException
 
-import Base: +, -, *, \, &, |, $, .+, .-, .*, ./, .\, .^, .<, .!=, ==
+import Base: +, -, *, /, \, &, |, $, .+, .-, .*, ./, .\, .^, .<, .!=, ==
 import Base: A_mul_B!, Ac_mul_B, Ac_mul_B!, At_mul_B, At_mul_B!, At_ldiv_B, Ac_ldiv_B, A_ldiv_B!
 import Base.LinAlg: At_ldiv_B!, Ac_ldiv_B!
 
diff --git a/base/sparse/sparsevector.jl b/base/sparse/sparsevector.jl
index 83526e6bc097b..4fc552978a653 100644
--- a/base/sparse/sparsevector.jl
+++ b/base/sparse/sparsevector.jl
@@ -1201,6 +1201,15 @@ scale(a::Complex, x::AbstractSparseVector) = scale(x, a)
 .*(x::AbstractSparseVector, a::Number) = scale(x, a)
 .*(a::Number, x::AbstractSparseVector) = scale(x, a)
 
+function /(x::AbstractSparseVector, a::Number)
+    if a == 0 || isnan(a)
+        throw(ArgumentError("Cannot divide sparse vector by provided argument"))
+    end
+    SparseVector(length(x), copy(x.nzind), x.nzval/a)
+end
+
+./(x::AbstractSparseVector, a::Number) = /(x,a)
+
 
 # dot
 
diff --git a/test/sparsedir/sparsevector.jl b/test/sparsedir/sparsevector.jl
index 069cf5c67eb45..07c4f504365aa 100644
--- a/test/sparsedir/sparsevector.jl
+++ b/test/sparsedir/sparsevector.jl
@@ -838,3 +838,25 @@ x = sparsevec(1:7, [3., 2., -1., 1., -2., -3., 3.], 15)
 @test collect(sort(x, by=abs)) == sort(collect(x), by=abs)
 @test collect(sort(x, by=sign)) == sort(collect(x), by=sign)
 @test collect(sort(x, by=inv)) == sort(collect(x), by=inv)
+
+# Issue 14111
+# test vector with no zeros
+s14111 = sparsevec([1., 2.5, -3., 8., -4])
+a14111 = sparsevec([0.4, 1., -1.2, 3.2, -1.6])
+@test exact_equal(s14111/2.5, a14111)
+@test exact_equal(s14111./2.5, a14111)
+# test vector with all zeros
+s14111 = sparsevec(Int64[], Float64[], 10)
+a14111 = sparsevec(Int64[], Float64[], 10)
+@test exact_equal(s14111/5., a14111)
+@test exact_equal(s14111./5., a14111)
+# test vector with both zero and nonzero
+s14111 = sparsevec([7., 0., -6., 3., 0., 2])
+a14111 = sparsevec([1, 3, 4, 6], [2.8, -2.4, 1.2, 0.8], 6)
+@test exact_equal(s14111/2.5, a14111)
+@test exact_equal(s14111./2.5, a14111)
+# test for division by illegal arguments
+@test_throws ArgumentError s14111/0.
+@test_throws ArgumentError s14111./0.
+@test_throws ArgumentError s14111/NaN
+@test_throws ArgumentError s14111./NaN