From d2d8122daafc87b47e60ae311a03c28050ca4f73 Mon Sep 17 00:00:00 2001
From: nhz2 <nhz2@cornell.edu>
Date: Mon, 24 Aug 2026 15:21:39 -0400
Subject: [PATCH] Remove Libz

---
 src/registry.jl  | 29 +++++++++++++----------------
 test/loadsave.jl |  4 ----
 2 files changed, 13 insertions(+), 20 deletions(-)

diff --git a/src/registry.jl b/src/registry.jl
index a5575f5..ab6a115 100644
--- a/src/registry.jl
+++ b/src/registry.jl
@@ -77,6 +77,12 @@ detect_compressed(io, len=getlength(io); kwargs...) = detect_compressor(io, len;
 const compressed_fits_exten = r"\.(fit|fits|fts|FIT|FITS|FTS)\.(gz|GZ)\>"
 name_matches_compressed_fits(io) = (:name ∈ propertynames(io)) && endswith(io.name, compressed_fits_exten)
 
+# We only fall back to treating a bare
+# compressed stream as RData when the filename actually carries an RData
+# extension; otherwise `detect_rdata` would claim any compressed file.
+const rdata_exten = r"\.(rda|RData|rdata)\>"
+name_matches_rdata(io) = (:name ∈ propertynames(io)) && endswith(io.name, rdata_exten)
+
 # test for RD?n magic sequence at the beginning of R data input stream
 function detect_rdata(io)
     seekstart(io)
@@ -98,11 +104,14 @@ function detect_rdata(io)
         return true
     end
     checked_match(io) && return true
-    return detect_compressed(io; formats=["GZIP", "BZIP2", "XZ"]) && !name_matches_compressed_fits(io)
+    return name_matches_rdata(io) && detect_compressed(io; formats=["GZIP", "BZIP2", "XZ"])
 end
 
 add_format(format"RData", detect_rdata, [".rda", ".RData", ".rdata"], [idRData, LOAD])
 
+const rdata_single_exten = r"\.rds\>"
+name_matches_rdata_single(io) = (:name ∈ propertynames(io)) && endswith(io.name, rdata_single_exten)
+
 function detect_rdata_single(io)
     seekstart(io)
     function checked_match(io)
@@ -119,12 +128,14 @@ function detect_rdata_single(io)
 
     res = checked_match(io)
     if !res
-        res = detect_compressed(io; formats=["GZIP", "BZIP2", "XZ"]) && !name_matches_compressed_fits(io)
+        res = name_matches_rdata_single(io) && detect_compressed(io; formats=["GZIP", "BZIP2", "XZ"])
     end
     seekstart(io)
     return res
 end
 
+add_format(format"RDataSingle", detect_rdata_single, [".rds"], [idRData, LOAD])
+
 function detect_excel(io)
     # All OOXML Excel files are ZIPs starting with PK\x03\x04
     magic = try
@@ -138,8 +149,6 @@ function detect_excel(io)
     # so just claiming the ZIP magic is sufficient to beat NPZ.
 end
 
-add_format(format"RDataSingle", detect_rdata_single, [".rds"], [idRData, LOAD])
-
 add_format(format"AVSfld", "# AVS", [".fld"], [idAVSfldIO])
 add_format(format"CSV", (), [".csv"], [idCSVFiles])
 add_format(format"TSV", (), [".tsv"], [idCSVFiles])
@@ -507,18 +516,6 @@ end
 add_format(format"STL_ASCII", detect_stlascii, [".stl", ".STL"], [idMeshIO])
 add_format(format"STL_BINARY", detect_stlbinary, [".stl", ".STL"], [idMeshIO])
 
-# GZip has two simple magic bytes [0x1f, 0x8b] but we don't want to dispatch to Libz
-# for file extensions like .fits.gz
-function detect_gzip(io)
-    if name_matches_compressed_fits(io)
-        return false
-    end
-    getlength(io) >= 2 || return false
-    magic = read!(io, Vector{UInt8}(undef, 2))
-    return magic == [0x1f, 0x8b]
-end
-add_format(format"GZIP", detect_gzip, ".gz", [:Libz => UUID("2ec943e9-cfe8-584d-b93d-64dcb6d567b7")])
-
 
 # Astro Data
 # FITS files are often gziped and given the extension ".fits.gz". We want to load those directly and not dispatch to Libz
diff --git a/test/loadsave.jl b/test/loadsave.jl
index 6149373..2b0610f 100644
--- a/test/loadsave.jl
+++ b/test/loadsave.jl
@@ -8,7 +8,6 @@ module TestLoadSave
     load(file::File{format"PBMText"})   = "PBMText"
     load(file::File{format"PBMBinary"}) = "PBMBinary"
     load(file::File{format"JLD"})       = "JLD"
-    load(file::File{format"GZIP"})      = "GZIP"
 end
 module TestLoadSave2
     import FileIO: File, @format_str
@@ -33,7 +32,6 @@ end
             add_loader(format"PBMBinary", TestLoadSave)
             add_loader(format"HDF5", TestLoadSave2)
             add_loader(format"JLD", TestLoadSave)
-            add_loader(format"GZIP", TestLoadSave)
             add_loader(format"BIB", TestLoadSave2)
             add_loader(format"DCM", TestLoadSave2)
 
@@ -51,8 +49,6 @@ end
             @test load(joinpath(fp,"file2.h5")) == "HDF5"
             # JLD file saved with .jld extension
             @test load(joinpath(fp,"file.jld")) == "JLD"
-            # GZIP file saved with .gz extension
-            @test load(joinpath(fp,"file.csv.gz")) == "GZIP"
             # Bibliography file saved with .bib extension
             @test load(joinpath(fp,"file.bib")) == "BIB"
             # DICOM file saved with .dcm extension