PArrays: Collect views for own_values if needed

Required for Julia < 1.9

src/HYPRE.jl

@@ -336,6 +336,14 @@ end
 # PartitionedArrays.PSparseMatrix -> HYPREMatrix #
 ##################################################
 
+function subarray_unsafe_supported()
+    # Wrapping of SubArrays as raw pointers may or may not be supported
+    # depending on the Julia version. If this is not supported, we have to fall
+    # back to allocation of an intermediate buffer. This logic can be removed if
+    # HYPRE.jl drops support for Julia < 1.9.
+    return @static Int(VERSION.minor) > 8 || Int(VERSION.major) > 1
+end
+
 # TODO: This has some duplicated code with to_hypre_data(::SparseMatrixCSC, ilower, iupper)
 function Internals.to_hypre_data(A::SparseMatrixCSC, r::AbstractLocalIndices, c::AbstractLocalIndices)
     g_to_l_rows = global_to_local(r) # Not sure about this assert
@@ -404,7 +412,6 @@ function Internals.to_hypre_data(A::SparseMatrixCSR, r::AbstractLocalIndices, c:
     @assert g_to_l_rows.own_to_local isa UnitRange && g_to_l_rows.own_to_local.start == 1
 
     n_local_rows = own_length(r)
-    n_local_cols = own_length(c)
     ilower = l_to_g_rows[1]
     iupper = l_to_g_rows[n_local_rows]
 
@@ -546,7 +553,16 @@ function Base.copy!(dst::PVector, src::HYPREVector)
         iu_src_part = o_to_g[end]
         nvalues = HYPRE_Int(iu_src_part - il_src_part + 1)
         indices = collect(HYPRE_BigInt, il_src_part:iu_src_part)
-        @check HYPRE_IJVectorGetValues(src, nvalues, indices, ov)
+        values = collect(HYPRE_Complex, ov)
+        if subarray_unsafe_supported()
+            values = ov
+        else
+            values = collect(HYPRE_Complex, ov)
+        end
+        @check HYPRE_IJVectorGetValues(src, nvalues, indices, values)
+        if !subarray_unsafe_supported()
+            @. ov = values
+        end
     end
     return dst
 end
@@ -561,7 +577,12 @@ function Base.copy!(dst::HYPREVector, src::PVector)
         iupper_src_part = o_to_g[end]
         nvalues = HYPRE_Int(iupper_src_part - ilower_src_part + 1)
         indices = collect(HYPRE_BigInt, ilower_src_part:iupper_src_part)
-        @check HYPRE_IJVectorSetValues(dst, nvalues, indices, ov)
+        if subarray_unsafe_supported()
+            values = ov
+        else
+            values = collect(HYPRE_Complex, ov)
+        end
+        @check HYPRE_IJVectorSetValues(dst, nvalues, indices, values)
     end
     # TODO: It shouldn't be necessary to assemble here since we only set owned rows (?)
     # @check HYPRE_IJVectorAssemble(dst)