From 820c08b896e408d9ed1e064ada8f9138dd6a3a6b Mon Sep 17 00:00:00 2001
From: Jeff Bezanson <jeff.bezanson@gmail.com>
Date: Mon, 18 Jul 2022 15:02:46 -0400
Subject: [PATCH] fix #45825, BitArray methods assuming 1-indexing of
 AbstractArray (#45835)

---
 base/abstractarray.jl | 10 +++++---
 base/bitarray.jl      | 53 +++++++++++++++++++++++--------------------
 test/bitarray.jl      | 35 ++++++++++++++++++++++++++++
 3 files changed, 70 insertions(+), 28 deletions(-)

diff --git a/base/abstractarray.jl b/base/abstractarray.jl
index b5b74bd8446c0..e97359cb87fcf 100644
--- a/base/abstractarray.jl
+++ b/base/abstractarray.jl
@@ -1035,6 +1035,10 @@ julia> y
 """
 function copyto!(dest::AbstractArray, src::AbstractArray)
     isempty(src) && return dest
+    if dest isa BitArray
+        # avoid ambiguities with other copyto!(::AbstractArray, ::SourceArray) methods
+        return _copyto_bitarray!(dest, src)
+    end
     src′ = unalias(dest, src)
     copyto_unaliased!(IndexStyle(dest), dest, IndexStyle(src′), src′)
 end
@@ -1139,10 +1143,10 @@ function copyto!(B::AbstractVecOrMat{R}, ir_dest::AbstractRange{Int}, jr_dest::A
     return B
 end
 
-function copyto_axcheck!(dest, src)
-    @noinline checkaxs(axd, axs) = axd == axs || throw(DimensionMismatch("axes must agree, got $axd and $axs"))
+@noinline _checkaxs(axd, axs) = axd == axs || throw(DimensionMismatch("axes must agree, got $axd and $axs"))
 
-    checkaxs(axes(dest), axes(src))
+function copyto_axcheck!(dest, src)
+    _checkaxs(axes(dest), axes(src))
     copyto!(dest, src)
 end
 
diff --git a/base/bitarray.jl b/base/bitarray.jl
index 73f274df44a85..71d83b5b58f56 100644
--- a/base/bitarray.jl
+++ b/base/bitarray.jl
@@ -501,40 +501,42 @@ function Array{T,N}(B::BitArray{N}) where {T,N}
 end
 
 BitArray(A::AbstractArray{<:Any,N}) where {N} = BitArray{N}(A)
+
 function BitArray{N}(A::AbstractArray{T,N}) where N where T
     B = BitArray(undef, convert(Dims{N}, size(A)::Dims{N}))
-    Bc = B.chunks
-    l = length(B)
+    _checkaxs(axes(B), axes(A))
+    _copyto_bitarray!(B, A)
+    return B::BitArray{N}
+end
+
+function _copyto_bitarray!(B::BitArray, A::AbstractArray)
+    l = length(A)
     l == 0 && return B
-    ind = 1
+    l > length(B) && throw(BoundsError(B, length(B)+1))
+    Bc = B.chunks
+    nc = num_bit_chunks(l)
+    Ai = first(eachindex(A))
     @inbounds begin
-        for i = 1:length(Bc)-1
+        for i = 1:nc-1
             c = UInt64(0)
             for j = 0:63
-                c |= (UInt64(convert(Bool, A[ind])::Bool) << j)
-                ind += 1
+                c |= (UInt64(convert(Bool, A[Ai])::Bool) << j)
+                Ai = nextind(A, Ai)
             end
             Bc[i] = c
         end
         c = UInt64(0)
-        for j = 0:_mod64(l-1)
-            c |= (UInt64(convert(Bool, A[ind])::Bool) << j)
-            ind += 1
+        tail = _mod64(l - 1) + 1
+        for j = 0:tail-1
+            c |= (UInt64(convert(Bool, A[Ai])::Bool) << j)
+            Ai = nextind(A, Ai)
         end
-        Bc[end] = c
+        msk = _msk_end(tail)
+        Bc[nc] = (c & msk) | (Bc[nc] & ~msk)
     end
     return B
 end
 
-function BitArray{N}(A::Array{Bool,N}) where N
-    B = BitArray(undef, size(A))
-    Bc = B.chunks
-    l = length(B)
-    l == 0 && return B
-    copy_to_bitarray_chunks!(Bc, 1, A, 1, l)
-    return B::BitArray{N}
-end
-
 reinterpret(::Type{Bool}, B::BitArray, dims::NTuple{N,Int}) where {N} = reinterpret(B, dims)
 reinterpret(B::BitArray, dims::NTuple{N,Int}) where {N} = reshape(B, dims)
 
@@ -721,24 +723,25 @@ function _unsafe_setindex!(B::BitArray, X::AbstractArray, I::BitArray)
     lx = length(X)
     last_chunk_len = _mod64(length(B)-1)+1
 
-    c = 1
+    Xi = first(eachindex(X))
+    lastXi = last(eachindex(X))
     for i = 1:lc
         @inbounds Imsk = Ic[i]
         @inbounds C = Bc[i]
         u = UInt64(1)
         for j = 1:(i < lc ? 64 : last_chunk_len)
             if Imsk & u != 0
-                lx < c && throw_setindex_mismatch(X, c)
-                @inbounds x = convert(Bool, X[c])
+                Xi > lastXi && throw_setindex_mismatch(X, count(I))
+                @inbounds x = convert(Bool, X[Xi])
                 C = ifelse(x, C | u, C & ~u)
-                c += 1
+                Xi = nextind(X, Xi)
             end
             u <<= 1
         end
         @inbounds Bc[i] = C
     end
-    if length(X) != c-1
-        throw_setindex_mismatch(X, c-1)
+    if Xi != nextind(X, lastXi)
+        throw_setindex_mismatch(X, count(I))
     end
     return B
 end
diff --git a/test/bitarray.jl b/test/bitarray.jl
index d17a9856596a4..3a528d4391a82 100644
--- a/test/bitarray.jl
+++ b/test/bitarray.jl
@@ -1787,3 +1787,38 @@ end
         @test all(bitarray[rangein, rangeout] .== true)
     end
 end
+
+# issue #45825
+
+isdefined(Main, :OffsetArrays) || @eval Main include("testhelpers/OffsetArrays.jl")
+using .Main.OffsetArrays
+
+let all_false = OffsetArray(falses(2001), -1000:1000)
+    @test !any(==(true), all_false)
+    # should be run with --check-bounds=yes
+    @test_throws DimensionMismatch BitArray(all_false)
+    all_false = OffsetArray(falses(2001), 1:2001)
+    @test !any(==(true), BitArray(all_false))
+    all_false = OffsetArray(falses(100, 100), 0:99, -1:98)
+    @test !any(==(true), all_false)
+    @test_throws DimensionMismatch BitArray(all_false)
+    all_false = OffsetArray(falses(100, 100), 1:100, 1:100)
+    @test !any(==(true), all_false)
+end
+let a = falses(1000),
+    msk = BitArray(rand(Bool, 1000)),
+    n = count(msk),
+    b = OffsetArray(rand(Bool, n), (-n÷2):(n÷2)-iseven(n))
+    a[msk] = b
+    @test a[msk] == collect(b)
+    a = falses(100, 100)
+    msk = BitArray(rand(Bool, 100, 100))
+    n = count(msk)
+    b = OffsetArray(rand(Bool, 1, n), 1:1, (-n÷2):(n÷2)-iseven(n))
+    a[msk] = b
+    @test a[msk] == vec(collect(b))
+end
+let b = trues(10)
+    copyto!(b, view([0,0,0], :))
+    @test b == [0,0,0,1,1,1,1,1,1,1]
+end