Fix bug in dense2ind and add tests for copy (#37855)

JuliaLang · Oct 3, 2020 · 1b3ddd4 · 1b3ddd4
1 parent defde49
commit 1b3ddd4
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Showing 2 changed files with 8 additions and 4 deletions.
diff --git a/stdlib/SparseArrays/src/sparsevector.jl b/stdlib/SparseArrays/src/sparsevector.jl
@@ -405,15 +405,14 @@ sparse(a::AbstractVector) = sparsevec(a)
 
 function _dense2indval!(nzind::Vector{Ti}, nzval::Vector{Tv}, s::AbstractArray{Tv}) where {Tv,Ti}
     require_one_based_indexing(s)
-    cap = length(nzind);
+    cap = length(nzind)
     @assert cap == length(nzval)
     n = length(s)
     c = 0
-    @inbounds for i = 1:n
-        v = s[i]
+    @inbounds for (i, v) in enumerate(s)
         if !iszero(v)
             if c >= cap
-                cap *= 2
+                cap = (cap == 0) ? 1 : 2*cap
                 resize!(nzind, cap)
                 resize!(nzval, cap)
             end

diff --git a/stdlib/SparseArrays/test/sparsevector.jl b/stdlib/SparseArrays/test/sparsevector.jl
@@ -431,6 +431,11 @@ end
         copyto!(x2, x) # copyto!(SparseVector, AbstractVector)
         @test Vector(x2) == collect(x)
     end
+    let x = 1:9, x1 = spzeros(length(x)), x2 = spzeros(length(x)-1)
+        @test_throws ArgumentError copy!(x2, x)
+        copy!(x1, convert.(eltype(x1), collect(x))) # copy!(SparseVector, AbstractVector)
+        @test Vector(x1) == collect(x)
+    end
 end
 @testset "vec/reinterpret/float/complex" begin
     a = SparseVector(8, [2, 5, 6], Int32[12, 35, 72])