From 894454c294120c4bfc3b228e38dae8c9da85199d Mon Sep 17 00:00:00 2001
From: Oscar Smith <oscardssmith@gmail.com>
Date: Thu, 8 Aug 2024 10:51:48 -0400
Subject: [PATCH] re-add `unsafe_convert` for Reinterpret and Reshaped array
 (#55226)

Fxes https://github.com/JuliaLang/julia/issues/54725

(cherry picked from commit f0a2a7a0a9438433eb1ac824bd09627ab8fd0586)
---
 base/reinterpretarray.jl | 1 +
 base/reshapedarray.jl    | 1 +
 test/ccall.jl            | 5 +++++
 3 files changed, 7 insertions(+)

diff --git a/base/reinterpretarray.jl b/base/reinterpretarray.jl
index d74a043293a3a..d31f3ebb5dd2d 100644
--- a/base/reinterpretarray.jl
+++ b/base/reinterpretarray.jl
@@ -373,6 +373,7 @@ has_offset_axes(a::ReinterpretArray) = has_offset_axes(a.parent)
 
 elsize(::Type{<:ReinterpretArray{T}}) where {T} = sizeof(T)
 cconvert(::Type{Ptr{T}}, a::ReinterpretArray{T,N,S} where N) where {T,S} = cconvert(Ptr{S}, a.parent)
+unsafe_convert(::Type{Ptr{T}}, a::ReinterpretArray{T,N,S} where N) where {T,S} = Ptr{T}(unsafe_convert(Ptr{S},a.parent))
 
 @propagate_inbounds function getindex(a::NonReshapedReinterpretArray{T,0,S}) where {T,S}
     if isprimitivetype(T) && isprimitivetype(S)
diff --git a/base/reshapedarray.jl b/base/reshapedarray.jl
index c7ae1e3a25cd1..fb5a930bd1c32 100644
--- a/base/reshapedarray.jl
+++ b/base/reshapedarray.jl
@@ -307,6 +307,7 @@ setindex!(A::ReshapedRange, val, index::ReshapedIndex) = _rs_setindex!_err()
 @noinline _rs_setindex!_err() = error("indexed assignment fails for a reshaped range; consider calling collect")
 
 cconvert(::Type{Ptr{T}}, a::ReshapedArray{T}) where {T} = cconvert(Ptr{T}, parent(a))
+unsafe_convert(::Type{Ptr{T}}, a::ReshapedArray{T}) where {T} = unsafe_convert(Ptr{T}, a.parent)
 
 # Add a few handy specializations to further speed up views of reshaped ranges
 const ReshapedUnitRange{T,N,A<:AbstractUnitRange} = ReshapedArray{T,N,A,Tuple{}}
diff --git a/test/ccall.jl b/test/ccall.jl
index 8b1fefdfc66e4..8fe3c8cbefe03 100644
--- a/test/ccall.jl
+++ b/test/ccall.jl
@@ -1937,3 +1937,8 @@ end
 
 # issue #52025
 @test Base.unsafe_convert(Ptr{Ptr{Cchar}}, Base.cconvert(Ptr{Ptr{Cchar}}, map(pointer, ["ab"]))) isa Ptr{Ptr{Cchar}}
+
+#issue #54725
+for A in (reinterpret(UInt, [0]), reshape([0, 0], 1, 2))
+    @test pointer(A) == Base.unsafe_convert(Ptr{Cvoid}, A) == Base.unsafe_convert(Ptr{Int}, A)
+end