From 6760bd47d23fdd2a6d239891651ad46dba336f21 Mon Sep 17 00:00:00 2001
From: JonasIsensee <jonas.isensee@web.de>
Date: Fri, 19 Jan 2024 11:37:38 +0100
Subject: [PATCH] add method for mutable custom serialization (#537)

---
 src/data/custom_serialization.jl |  7 +++++++
 test/loadsave.jl                 | 10 ++++++++++
 2 files changed, 17 insertions(+)

diff --git a/src/data/custom_serialization.jl b/src/data/custom_serialization.jl
index a15f432b..3100dd76 100644
--- a/src/data/custom_serialization.jl
+++ b/src/data/custom_serialization.jl
@@ -52,6 +52,13 @@ jlconvert_canbeuninitialized(::ReadRepresentation{T,CustomSerialization{S,ODR}})
 jlconvert_isinitialized(::ReadRepresentation{T,CustomSerialization{S,ODR}}, ptr::Ptr) where {T,S,ODR} =
     jlconvert_isinitialized(ReadRepresentation{S,ODR}(), ptr)
 
+function jlconvert(::ReadRepresentation{T,CustomSerialization{S,RelOffset}},
+        f::JLDFile, ptr::Ptr, header_offset::RelOffset) where {T,S}
+    # Concerns objects whose custom serialization is itself only referenced by a RelOffset
+    # This be important when the original object is mutable
+    offset = jlunsafe_load(pconvert(Ptr{RelOffset}, ptr))
+    return rconvert(T, load_dataset(f, offset))
+end
 
 function jlconvert(::ReadRepresentation{T,CustomSerialization{S,ODR}},
           f::JLDFile, ptr::Ptr, header_offset::RelOffset) where {T,S,ODR}
diff --git a/test/loadsave.jl b/test/loadsave.jl
index 19ed4792..0ca9204b 100644
--- a/test/loadsave.jl
+++ b/test/loadsave.jl
@@ -739,4 +739,14 @@ end
         jldsave("testopempty.jld2"; op)
         @test op == load("testopempty.jld2", "op")
     end
+end
+
+@testset "Issue #536 reading directly after writing" begin
+    cd(mktempdir()) do 
+        x = (1, Dict(2=>3))
+        jldopen("test.jld2", "w") do f
+            f["x"] = x
+            @test x == f["x"]
+        end
+    end
 end
\ No newline at end of file