Fix boundscheck in suboperator (#291)

* Fix boundscheck in suboperator

* Empty indices

Author: jishnub

src/Operators/SubOperator.jl

@@ -17,10 +17,11 @@ _checkbounds(A::Operator,kr::Union{Colon,InfRanges},jr)::Bool =
 _checkbounds(A::Operator,kr,jr::Union{Colon,InfRanges})::Bool =
     !(maximum(kr) > size(A,1)  || minimum(kr) < 1 )
 
-_checkbounds(A::Operator,kr,jr)::Bool =
-    !(!isempty(kr) && (maximum(kr) > size(A,1) || minimum(kr) < 1)) ||
-    (!isempty(jr) && (maximum(jr) > size(A,2) || minimum(jr) < 1))
-
+function _checkbounds(A::Operator,kr,jr)::Bool
+    (isempty(kr) || isempty(jr)) && return true
+    (1 <= minimum(kr) <= maximum(kr) <= size(A,1)) &&
+    (1 <= minimum(jr) <= maximum(jr) <= size(A,2))
+end
 
 _checkbounds(A::Operator,K::Block,J::Block)::Bool =
      1 ≤ first(K.n[1]) ≤ length(blocklengths(rangespace(A))) &&

src/Operators/general/algebra.jl

@@ -387,7 +387,7 @@ end
 _rettype(::Type{BandedMatrix{T}}) where {T} = BandedMatrix{T,Matrix{T},Base.OneTo{Int}}
 _rettype(T) = T
 for TYP in (:Matrix, :BandedMatrix, :RaggedMatrix)
-    @eval function $TYP(V::SubOperator{T,TO,Tuple{UnitRange{Int},UnitRange{Int}}}) where {T,TO<:TimesOperator}
+    @eval function $TYP(V::SubOperator{T,<:TimesOperator,NTuple{2,UnitRange{Int}}}) where {T}
         P = parent(V)
 
         if isbanded(P)
@@ -407,7 +407,7 @@ for TYP in (:Matrix, :BandedMatrix, :RaggedMatrix)
 
         if maximum(kr) > size(P,1) || maximum(jr) > size(P,2) ||
             minimum(kr) < 1 || minimum(jr) < 1
-            throw(BoundsError())
+            throw(BoundsError(P, (kr,jr)))
         end
 
         @assert length(P.ops) ≥ 2
@@ -458,7 +458,7 @@ for TYP in (:Matrix, :BandedMatrix, :RaggedMatrix)
 end
 
 for TYP in (:BlockBandedMatrix, :BandedBlockBandedMatrix)
-    @eval function $TYP(V::SubOperator{T,TO,Tuple{BlockRange1,BlockRange1}}) where {T,TO<:TimesOperator}
+    @eval function $TYP(V::SubOperator{T,<:TimesOperator,Tuple{BlockRange1,BlockRange1}}) where {T}
         P = parent(V)
         KR,JR = parentindices(V)
 
@@ -469,7 +469,7 @@ for TYP in (:BlockBandedMatrix, :BandedBlockBandedMatrix)
 
         if Int(maximum(KR)) > blocksize(P,1) || Int(maximum(JR)) > blocksize(P,2) ||
             Int(minimum(KR)) < 1 || Int(minimum(JR)) < 1
-            throw(BoundsError())
+            throw(BoundsError(P, (KR,JR)))
         end
 
 

test/runtests.jl

@@ -2,6 +2,7 @@ using ApproxFunBase, LinearAlgebra, Random, Test
 using ApproxFunBase: ∞
 using Aqua
 using SpecialFunctions
+using BandedMatrices
 
 @testset "Project quality" begin
     Aqua.test_all(ApproxFunBase, ambiguities=false)
@@ -265,6 +266,11 @@ end
                 @test size(V) == (1,)
                 @test all(==(1), V)
             end
+            A = Fun(PointSpace(1:4))
+            B = Multiplication(A, space(A))
+            C = B * B
+            @test_throws BoundsError @view C[1:2, 0:2]
+            @test_throws BoundsError @view C[1:10, 1:2]
         end
     end
     @testset "conversion to a matrix" begin