avoid overflow in nfield loading

JuliaIO · May 13, 2024 · dd3b2d5 · dd3b2d5
1 parent 7579dfb
commit dd3b2d5
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Showing 4 changed files with 20 additions and 2 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,3 +1,6 @@
+## 0.4.47
+ - fix loading structs with more than 256 fields (#558)
+
 ## 0.4.46
  - remove usage of `IOBuffer` internals
 

diff --git a/Project.toml b/Project.toml
@@ -1,6 +1,6 @@
 name = "JLD2"
 uuid = "033835bb-8acc-5ee8-8aae-3f567f8a3819"
-version = "0.4.46"
+version = "0.4.47"
 
 [deps]
 FileIO = "5789e2e9-d7fb-5bc7-8068-2c6fae9b9549"

diff --git a/src/datatypes.jl b/src/datatypes.jl
@@ -243,7 +243,7 @@ end
 function jlread(io::IO, ::Type{CompoundDatatype})
     dt = jlread(io, BasicDatatype)
     version = dt.class >> 4
-    nfields = UInt16(dt.bitfield1) | UInt16(dt.bitfield2 << 8)
+    nfields = UInt16(dt.bitfield1) | UInt16(dt.bitfield2) << 8
     dt.bitfield3 == 0 || throw(UnsupportedFeatureException())
 
     names = Vector{Symbol}(undef, nfields)

diff --git a/test/loadsave.jl b/test/loadsave.jl
@@ -749,4 +749,19 @@ end
             @test x == f["x"]
         end
     end
+end
+
+@testset "Issue #558 a struct with 256 fields" begin
+    fields = [Symbol("field",i) for i in 1:256]
+    @eval struct Structwithmanyfields
+        $(fields...)
+    end
+    # Fill the struct
+    obj = Structwithmanyfields(ntuple(i -> i, 256)...)
+
+    cd(mktempdir()) do 
+        save_object("myStruct.jld2", obj)
+        loaded = load_object("myStruct.jld2")
+        @test loaded isa Structwithmanyfields
+    end
 end