From ec49242dba9ae327968108877d7b12e768445b1d Mon Sep 17 00:00:00 2001
From: Colinxu2020 <63941938+colinxu2020@users.noreply.github.com>
Date: Tue, 12 May 2026 22:47:02 +0800
Subject: [PATCH 1/4] Remove steal flag from bytes concatenation

---
 mypyc/primitives/bytes_ops.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/mypyc/primitives/bytes_ops.py b/mypyc/primitives/bytes_ops.py
index 2db4879441025..96e8069f317ed 100644
--- a/mypyc/primitives/bytes_ops.py
+++ b/mypyc/primitives/bytes_ops.py
@@ -64,7 +64,6 @@
     return_type=bytes_rprimitive,
     c_function_name="CPyBytes_Concat",
     error_kind=ERR_MAGIC,
-    steals=[True, False],
 )
 
 # bytes * int

From 9010e28b421e9b12d79ca0bbfaaeb5aa5428883d Mon Sep 17 00:00:00 2001
From: Colinxu2020 <colinxu2020@gmail.com>
Date: Tue, 12 May 2026 23:30:46 +0800
Subject: [PATCH 2/4] Add Tests for Bytes Concat

---
 mypyc/test-data/irbuild-bytes.test | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/mypyc/test-data/irbuild-bytes.test b/mypyc/test-data/irbuild-bytes.test
index b149e0a96cdf6..740475aa7ba1e 100644
--- a/mypyc/test-data/irbuild-bytes.test
+++ b/mypyc/test-data/irbuild-bytes.test
@@ -299,3 +299,26 @@ def foo(b: bytes, ba: bytearray) -> None:
 [out]
 main:7: error: Argument 1 to "bytes_func" has incompatible type "bytearray"; expected "bytes"
 main:8: error: Argument 1 to "bytearray_func" has incompatible type "bytes"; expected "bytearray"
+
+[case testBytesConcatRefcount]
+def f(a: bytes, b: bytes) -> bytes:
+    return b"1" + b
+[out]
+def f(a, b):
+    a, b, r0, r1 :: bytes
+L0:
+    r0 = b'1'
+    r1 = CPyBytes_Concat(r0, b)
+    return r1
+
+[case testChainedBytesConcatRefcount]
+def f(a: bytes, b: bytes, c: bytes) -> bytes:
+    return b"1" + b + c
+[out]
+def f(a, b, c):
+    a, b, c, r0, r1, r2 :: bytes
+L0:
+    r0 = b'1'
+    r1 = CPyBytes_Concat(r0, b)
+    r2 = CPyBytes_Concat(r1, c)
+    return r2

From 864a11bc2e28f125a3731e51b9d6a30bdb3b43d0 Mon Sep 17 00:00:00 2001
From: Colinxu2020 <colinxu2020@gmail.com>
Date: Wed, 13 May 2026 08:08:47 +0800
Subject: [PATCH 3/4] fix tests

---
 mypyc/test-data/irbuild-bytes.test | 23 -----------------------
 mypyc/test-data/refcount.test      | 29 +++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 23 deletions(-)

diff --git a/mypyc/test-data/irbuild-bytes.test b/mypyc/test-data/irbuild-bytes.test
index 740475aa7ba1e..b149e0a96cdf6 100644
--- a/mypyc/test-data/irbuild-bytes.test
+++ b/mypyc/test-data/irbuild-bytes.test
@@ -299,26 +299,3 @@ def foo(b: bytes, ba: bytearray) -> None:
 [out]
 main:7: error: Argument 1 to "bytes_func" has incompatible type "bytearray"; expected "bytes"
 main:8: error: Argument 1 to "bytearray_func" has incompatible type "bytes"; expected "bytearray"
-
-[case testBytesConcatRefcount]
-def f(a: bytes, b: bytes) -> bytes:
-    return b"1" + b
-[out]
-def f(a, b):
-    a, b, r0, r1 :: bytes
-L0:
-    r0 = b'1'
-    r1 = CPyBytes_Concat(r0, b)
-    return r1
-
-[case testChainedBytesConcatRefcount]
-def f(a: bytes, b: bytes, c: bytes) -> bytes:
-    return b"1" + b + c
-[out]
-def f(a, b, c):
-    a, b, c, r0, r1, r2 :: bytes
-L0:
-    r0 = b'1'
-    r1 = CPyBytes_Concat(r0, b)
-    r2 = CPyBytes_Concat(r1, c)
-    return r2
diff --git a/mypyc/test-data/refcount.test b/mypyc/test-data/refcount.test
index 2f03a159dfacb..8f9382a6335fe 100644
--- a/mypyc/test-data/refcount.test
+++ b/mypyc/test-data/refcount.test
@@ -2125,3 +2125,32 @@ L3:
     r8 = box(None, 1)
     inc_ref r8
     return r8
+
+[case testBytesConcatRefcount]
+def f(a: bytes, b: bytes) -> bytes:
+    return b"1" + a + b
+[out]
+def f(a, b):
+    a, b, r0, r1, r2 :: bytes
+L0:
+    r0 = b'1'
+    r1 = CPyBytes_Concat(r0, a)
+    r2 = CPyBytes_Concat(r1, b)
+    dec_ref r1
+    return r2
+
+[case testChainedBytesConcatRefcount]
+def f(a: bytes, b: bytes, c: bytes) -> bytes:
+    return b"1" + a + b + c
+[out]
+def f(a, b, c):
+    a, b, c, r0, r1, r2, r3 :: bytes
+L0:
+    r0 = b'1'
+    r1 = CPyBytes_Concat(r0, a)
+    r2 = CPyBytes_Concat(r1, b)
+    dec_ref r1
+    r3 = CPyBytes_Concat(r2, c)
+    dec_ref r2
+    return r3
+

From bcb04d03828f6e739ccd975cf0b322f12a47f470 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Wed, 13 May 2026 00:10:27 +0000
Subject: [PATCH 4/4] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 mypyc/test-data/refcount.test | 1 -
 1 file changed, 1 deletion(-)

diff --git a/mypyc/test-data/refcount.test b/mypyc/test-data/refcount.test
index 8f9382a6335fe..918c84ee3b0ad 100644
--- a/mypyc/test-data/refcount.test
+++ b/mypyc/test-data/refcount.test
@@ -2153,4 +2153,3 @@ L0:
     r3 = CPyBytes_Concat(r2, c)
     dec_ref r2
     return r3
-