From fa735fd1d125648b22a2d77fb5359dcea77fac54 Mon Sep 17 00:00:00 2001
From: foreverallama <klockatoo@gmail.com>
Date: Fri, 5 Jun 2026 15:53:55 +0530
Subject: [PATCH 1/4] Fix: Return varname with opaque class object

---
 src/MAT_v5.jl | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/MAT_v5.jl b/src/MAT_v5.jl
index b25237e..084c8c4 100644
--- a/src/MAT_v5.jl
+++ b/src/MAT_v5.jl
@@ -441,10 +441,20 @@ function getvarnames(matfile::Matlabv5File)
                 error("Unexpected data type")
             end
 
-            read_element(f, matfile.swap_bytes, UInt32)
-            read_element(f, matfile.swap_bytes, Int32)
-            varnames[String(read_element(f, matfile.swap_bytes, UInt8))] = offset
+            flags = read_element(f, matfile.swap_bytes, UInt32)
+            class = flags[1] & 0xFF
+            if class != mxOPAQUE_CLASS
+                read_element(f, matfile.swap_bytes, Int32)
+            end
+
+            varname = String(read_element(f, matfile.swap_bytes, UInt8))
+            if varname == ""
+                # Skip unnamed variable (subsystem)
+                seek(matfile.ios, offset+nbytes+hbytes)
+                continue
+            end
 
+            varnames[varname] = offset
             seek(matfile.ios, offset+nbytes+hbytes)
         end
     end

From cf2f2f561574f8cf1f9abbadee120227907f1be6 Mon Sep 17 00:00:00 2001
From: foreverallama <klockatoo@gmail.com>
Date: Fri, 5 Jun 2026 16:07:20 +0530
Subject: [PATCH 2/4] Add test

---
 test/read.jl         |   8 ++++++++
 test/v7/varnames.mat | Bin 0 -> 634 bytes
 2 files changed, 8 insertions(+)
 create mode 100644 test/v7/varnames.mat

diff --git a/test/read.jl b/test/read.jl
index 0b2ab64..2967c12 100644
--- a/test/read.jl
+++ b/test/read.jl
@@ -418,3 +418,11 @@ let objtestfile = "char_array_old_null.mat"
     @test haskey(vars, "simple_string")
     @test vars["simple_string"] == "t\0e\0q\0i\0k\0b\0o\0n\0f\0x"
 end
+
+@testset "read variable names" begin
+    let objtestfile = "varnames.mat"
+        file = matopen(joinpath(dirname(@__FILE__), "v7", objtestfile))
+        var_name_dict = keys(file)
+        @test Set(var_name_dict) == Set(["a", "b", "c", "d"])
+    end
+end
diff --git a/test/v7/varnames.mat b/test/v7/varnames.mat
new file mode 100644
index 0000000000000000000000000000000000000000..7f5e7655586d4db3ed0ac739f66a41be5a71a520
GIT binary patch
literal 634
zcmeZu4DoSvQZUssQ1EpO(M`+DN!3vZ$Vn_o%P-2c0*X01nwjV*I2WZRmZYXA<mXu_
zxD{n8c$MZUD3~f3nphbbS{Yj^7#SFuDG&>i85tme(bJb7$kG7fiaC#y6A}y<lFSsI
zHC$3S!1dIa*-%-+*hqybQ*8l<vam5TgSY|1C6Ib;xcUuX^$ba3Y#a%#pClLNxGDHB
zU1AETbIbDcvzx%ipfi){CrFD2TuTO2iz84A%b^s5vxgqMej|T|BQ!WBXv)m#=MEfT
zPpMXT`MC8}a_gs?2dWfjFrJ#;VDR2Z@#H}R1~FZ>e1cA1!T@qIx3)CU$@vWTK<fE{
zUWRya#=%1e4zMk;Y?v{bktt$fjhn)`gvJXB2UwmO8&v&j`cdOh(<HfYK4*8GL|ez^
zhNlt>vufu4ZBBe<qA*jLBlJAS^2h^Ojx})#Wv9=0^6Go(Xn5#$^|!w&cevEQf&Wmt
zb1}QeUv{=T|Lhu;&EwQM#*`Y(P{<-6&hU{*A+E8-oS`r&PSv^4GcYaAirMc#iz|=q
zo&rWUnVg(gWeOjEPRN*WJMrK1_Ace)(nS_chwd~on%Ycw+jh|=VAqU=EeksoCoA?V
z%C_=uDraSWSCN!-phumX?a#|@pt{<NLH7K!>Po&JIwCpY3%}|AGJ^;D{7Mo5mmOJd
WIJi_ka6C|#bedU!fq}C`buj=$+}L~o

literal 0
HcmV?d00001


From a70712021609905fcb4a12c592b0b9f3ddea9c57 Mon Sep 17 00:00:00 2001
From: foreverallama <klockatoo@gmail.com>
Date: Fri, 5 Jun 2026 16:20:46 +0530
Subject: [PATCH 3/4] Tests for haskey and read

---
 test/read.jl | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/test/read.jl b/test/read.jl
index 2967c12..5f7b8ba 100644
--- a/test/read.jl
+++ b/test/read.jl
@@ -424,5 +424,23 @@ end
         file = matopen(joinpath(dirname(@__FILE__), "v7", objtestfile))
         var_name_dict = keys(file)
         @test Set(var_name_dict) == Set(["a", "b", "c", "d"])
+
+        @test haskey(file, "a")
+        @test haskey(file, "b")
+        @test haskey(file, "c")
+        @test haskey(file, "d")
+        @test !haskey(file, "e")
+
+        data = read(file, "a")
+        @test data == reshape([1.0; 2.0; 3.0], 3, 1)
+
+        data = read(file, "b")
+        @test data == "hello"
+
+        data = read(file, "c")
+        @test data == "stringstring"
+
+        data = read(file, "d")
+        @test data == reshape([4.0, 5.0, 6.0], 3, 1)
     end
 end

From e69ba3ffac63e7b007157fd002ebb05c4dff407c Mon Sep 17 00:00:00 2001
From: foreverallama <klockatoo@gmail.com>
Date: Sat, 6 Jun 2026 20:31:37 +0530
Subject: [PATCH 4/4] Version bump

---
 Project.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Project.toml b/Project.toml
index 23c392f..3e1f641 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "MAT"
 uuid = "23992714-dd62-5051-b70f-ba57cb901cac"
-version = "0.12.0"
+version = "0.12.1"
 
 [deps]
 CodecZlib = "944b1d66-785c-5afd-91f1-9de20f533193"