Add Int conversion for string lengths, document embedded basket limitation

src/bootstrap.jl

@@ -16,6 +16,15 @@ function unpack(io, tkey::TKey, refs::Dict{Int32, Any}, T::Type{RecoveredTBasket
     fKeylen = readtype(io, Int16)
     fCycle = readtype(io, Int16)
 
+    # Check if this is an embedded basket
+    # Embedded baskets have fNbytes <= fKeylen, meaning all data is inline
+    is_embedded = fNbytes <= fKeylen
+
+    # For embedded baskets, we still need to read through all the data
+    # to satisfy the parent TObjArray's byte count, even though we won't use it
+    # The embedded basket data is stored inline and we need to consume it
+
+    # Non-embedded basket handling (original logic for recovered baskets)
     # skipping class name, name and title
     seek(io, start + fKeylen - 18 - 1)
 

src/io.jl

@@ -35,7 +35,7 @@ function readtype(io, ::Type{T}) where T<:AbstractString
         length = readtype(io, UInt32)
     end
 
-    T(read(io, length))
+    T(read(io, Int(length)))
 end
 
 struct CString

test/issues.jl

@@ -109,3 +109,23 @@ end
     df = LazyTree(UnROOT.samplefile("TLeafC_pr342.root"), "G4Sim")
     @test all(df.Process[1:10] .== ["Radioactivation", "msc", "eIoni", "Transportation", "ionIoni", "Radioactivation", "msc", "eIoni", "ionIoni", "Radioactivation"])
 end
+
+# Issue: EOF when trying to open files with recovered/embedded baskets
+# Files with embedded baskets (fNbytes <= fKeylen) from premature closure
+# are not yet fully supported. This is a known limitation.
+# See: https://github.com/JuliaHEP/UnROOT.jl/issues/XXX
+@testset "Embedded baskets limitation" begin
+    # This test documents the known limitation with files containing embedded baskets
+    # Such files occur when ROOT files are closed prematurely (e.g., process crash)
+    # and ROOT's recovery mechanism stores uncompressed basket data inline
+
+    # TODO: Add test file with embedded baskets when support is implemented
+    # For now, this serves as documentation that such files are not yet supported
+
+    # Example of what should eventually work:
+    # f = UnROOT.samplefile("file_with_embedded_baskets.root")  
+    # tree = f["tree_name"]
+    # @test tree.fEntries > 0
+
+    @test_skip false  # Placeholder - remove when support is added
+end