From fcf5b7ef8319730df1de5df76cdebe427ae4a4c3 Mon Sep 17 00:00:00 2001
From: Josh Ware <josh.ware@healius.com.au>
Date: Thu, 19 Jan 2023 11:33:15 +1100
Subject: [PATCH 01/19] Fixed merge conflicts during recent pull

---
 src/encode.c | 32 ++++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/encode.c b/src/encode.c
index 21c42d915..33a2a37a7 100644
--- a/src/encode.c
+++ b/src/encode.c
@@ -1214,10 +1214,12 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
     char mct = 0;
     int sgnd = 0;
     Py_ssize_t fd = -1;
+    char * comment = NULL;
+    int add_plt = 0;
 
     if (!PyArg_ParseTuple(
             args,
-            "ss|OOOsOnOOOssbbn",
+            "ss|OOOsOnOOOssbbnzp",
             &mode,
             &format,
             &offset,
@@ -1233,7 +1235,9 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
             &cinema_mode,
             &mct,
             &sgnd,
-            &fd)) {
+            &fd,
+            &comment,
+            &add_plt)) {
         return NULL;
     }
 
@@ -1315,6 +1319,29 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
         }
     }
 
+    if (comment != NULL && strlen(comment) > 0) {
+        /* Size is stored as as an uint16, subtract 4 bytes for the header */
+        if (strlen(comment) >= 65531) {
+            PyErr_SetString(
+                PyExc_ValueError,
+                "JPEG 2000 comment is too long");
+            Py_DECREF(encoder);
+            return NULL;            
+        }
+
+        context->comment = strdup(comment);
+
+        if (context->comment == NULL) {
+            PyErr_SetString(
+                PyExc_MemoryError,
+                "Couldn't allocate memory for JPEG 2000 comment");
+            Py_DECREF(encoder);
+            return NULL;
+        }
+    } else {
+        context->comment = NULL;
+    }
+
     if (quality_layers && PySequence_Check(quality_layers)) {
         context->quality_is_in_db = strcmp(quality_mode, "dB") == 0;
         context->quality_layers = quality_layers;
@@ -1332,6 +1359,7 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
     context->cinema_mode = cine_mode;
     context->mct = mct;
     context->sgnd = sgnd;
+    context->add_plt = add_plt;
 
     return (PyObject *)encoder;
 }

From de43bc99c873fe0c752f5e303c4a40f954b61912 Mon Sep 17 00:00:00 2001
From: Josh Ware <josh.ware@healius.com.au>
Date: Thu, 19 Jan 2023 11:37:14 +1100
Subject: [PATCH 02/19] Added support for jpeg2000 comments and PLT marker
 segments

---
 Tests/test_file_jpeg2k.py            | 44 ++++++++++++++++++++++++++++
 docs/handbook/image-file-formats.rst | 13 ++++++++
 src/PIL/Jpeg2KImagePlugin.py         |  4 +++
 src/libImaging/Jpeg2K.h              |  6 ++++
 src/libImaging/Jpeg2KEncode.c        | 17 +++++++++++
 5 files changed, 84 insertions(+)

diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index 0229b2243..f52c33402 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -1,5 +1,6 @@
 import os
 import re
+import struct
 from io import BytesIO
 
 import pytest
@@ -371,3 +372,46 @@ def test_crashes(test_file):
                 im.load()
             except OSError:
                 pass
+
+
+def test_custom_comment():
+    output_stream = BytesIO()
+    unique_comment = "This is a unique comment, which should be found below"
+    test_card.save(output_stream, "JPEG2000", comment=unique_comment)
+    output_stream.seek(0)
+    data = output_stream.read()
+    # Lazy method to determine if the comment is in the image generated
+    assert(bytes(unique_comment, "utf-8") in data)
+
+
+def test_plt_marker():
+    # Search the start of the codesteam for the PLT box (id 0xFF58)
+    opj_version = re.search(r"(\d+\.\d+)\.\d+$", features.version_codec("jpg_2000"))
+    assert opj_version is not None
+
+    if float(opj_version[1]) >= 2.4:
+        out = BytesIO()
+        test_card.save(out, "JPEG2000", no_jp2=True, add_plt=True)
+        out.seek(0)
+        while True:
+            box_bytes = out.read(2)
+            if len(box_bytes) == 0:
+                # End of steam encounterd and no PLT or SOD
+                break
+            jp2_boxid = struct.unpack(">H", box_bytes)[0]
+
+            if jp2_boxid == 0xff4f:
+                # No length specifier for main header
+                continue
+            elif jp2_boxid == 0xff58:
+                # This is the PLT box we're looking for
+                return
+            elif jp2_boxid == 0xff93:
+                break
+                # SOD box encountered and no PLT, so it wasn't found
+
+            jp2_boxlength = struct.unpack(">H", out.read(2))[0]
+            out.seek(jp2_boxlength - 2, os.SEEK_CUR)
+
+        # The PLT box wasn't found
+        raise ValueError
diff --git a/docs/handbook/image-file-formats.rst b/docs/handbook/image-file-formats.rst
index a41ef7cf8..9128400ac 100644
--- a/docs/handbook/image-file-formats.rst
+++ b/docs/handbook/image-file-formats.rst
@@ -589,6 +589,19 @@ The :py:meth:`~PIL.Image.Image.save` method supports the following options:
 
     .. versionadded:: 9.1.0
 
+**comment**
+    Adds a custom comment to the file, replacing the default 
+    "Created by OpenJPEG version" comment.
+
+    .. versionadded:: 9.5.0
+
+**add_plt**
+    If ``True`` then include a PLT (packet length, tile-part header) marker 
+    segment in the produced file.
+    The default is to not include it.
+
+    .. versionadded:: 9.5.0
+
 .. note::
 
    To enable JPEG 2000 support, you need to build and install the OpenJPEG
diff --git a/src/PIL/Jpeg2KImagePlugin.py b/src/PIL/Jpeg2KImagePlugin.py
index 7457874c1..754010c7c 100644
--- a/src/PIL/Jpeg2KImagePlugin.py
+++ b/src/PIL/Jpeg2KImagePlugin.py
@@ -328,6 +328,8 @@ def _save(im, fp, filename):
     mct = info.get("mct", 0)
     signed = info.get("signed", False)
     fd = -1
+    comment = info.get("comment", None)
+    add_plt = info.get("add_plt", False)
 
     if hasattr(fp, "fileno"):
         try:
@@ -350,6 +352,8 @@ def _save(im, fp, filename):
         mct,
         signed,
         fd,
+        comment,
+        add_plt
     )
 
     ImageFile._save(im, fp, [("jpeg2k", (0, 0) + im.size, 0, kind)])
diff --git a/src/libImaging/Jpeg2K.h b/src/libImaging/Jpeg2K.h
index b28a0440a..65728be5d 100644
--- a/src/libImaging/Jpeg2K.h
+++ b/src/libImaging/Jpeg2K.h
@@ -97,6 +97,12 @@ typedef struct {
     /* PRIVATE CONTEXT (set by decoder) */
     const char *error_msg;
 
+    /* Custom comment */
+    char * comment;
+
+    /* Include PLT marker segment */
+    int add_plt;
+
 } JPEG2KENCODESTATE;
 
 /*
diff --git a/src/libImaging/Jpeg2KEncode.c b/src/libImaging/Jpeg2KEncode.c
index db1c5c0c9..bb280ae94 100644
--- a/src/libImaging/Jpeg2KEncode.c
+++ b/src/libImaging/Jpeg2KEncode.c
@@ -439,6 +439,10 @@ j2k_encode_entry(Imaging im, ImagingCodecState state) {
         params.tcp_mct = context->mct;
     }
 
+    if (context->comment) {
+        params.cp_comment = context->comment;
+    }
+
     params.prog_order = context->progression;
 
     params.cp_cinema = context->cinema_mode;
@@ -492,6 +496,14 @@ j2k_encode_entry(Imaging im, ImagingCodecState state) {
     opj_set_warning_handler(codec, j2k_warn, context);
     opj_setup_encoder(codec, &params, image);
 
+    /* Enabling PLT markers only supported in OpenJPEG 2.4.0 and up */
+#if ((OPJ_VERSION_MAJOR == 2 && OPJ_VERSION_MINOR >= 4) || OPJ_VERSION_MAJOR > 2)
+    if (context->add_plt) {
+        const char * plt_option[2] = {"PLT=YES", NULL};
+        opj_encoder_set_extra_options(codec, plt_option);
+    }
+#endif
+
     /* Start encoding */
     if (!opj_start_compress(codec, image, stream)) {
         state->errcode = IMAGING_CODEC_BROKEN;
@@ -624,7 +636,12 @@ ImagingJpeg2KEncodeCleanup(ImagingCodecState state) {
         free((void *)context->error_msg);
     }
 
+    if (context->comment) {
+        free((void *)context->comment);
+    }
+
     context->error_msg = NULL;
+    context->comment = NULL;
 
     return -1;
 }

From 41b3ac8aed826679485913f4e1c94320408016e0 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Thu, 19 Jan 2023 00:52:38 +0000
Subject: [PATCH 03/19] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 Tests/test_file_jpeg2k.py    | 8 ++++----
 src/PIL/Jpeg2KImagePlugin.py | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index f52c33402..6107075d5 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -381,7 +381,7 @@ def test_custom_comment():
     output_stream.seek(0)
     data = output_stream.read()
     # Lazy method to determine if the comment is in the image generated
-    assert(bytes(unique_comment, "utf-8") in data)
+    assert bytes(unique_comment, "utf-8") in data
 
 
 def test_plt_marker():
@@ -400,13 +400,13 @@ def test_plt_marker():
                 break
             jp2_boxid = struct.unpack(">H", box_bytes)[0]
 
-            if jp2_boxid == 0xff4f:
+            if jp2_boxid == 0xFF4F:
                 # No length specifier for main header
                 continue
-            elif jp2_boxid == 0xff58:
+            elif jp2_boxid == 0xFF58:
                 # This is the PLT box we're looking for
                 return
-            elif jp2_boxid == 0xff93:
+            elif jp2_boxid == 0xFF93:
                 break
                 # SOD box encountered and no PLT, so it wasn't found
 
diff --git a/src/PIL/Jpeg2KImagePlugin.py b/src/PIL/Jpeg2KImagePlugin.py
index 754010c7c..001dcf39c 100644
--- a/src/PIL/Jpeg2KImagePlugin.py
+++ b/src/PIL/Jpeg2KImagePlugin.py
@@ -353,7 +353,7 @@ def _save(im, fp, filename):
         signed,
         fd,
         comment,
-        add_plt
+        add_plt,
     )
 
     ImageFile._save(im, fp, [("jpeg2k", (0, 0) + im.size, 0, kind)])

From d55563ca2519765473f87271f4f39ebd75a9150e Mon Sep 17 00:00:00 2001
From: Josh Ware <josh@joshw.info>
Date: Thu, 19 Jan 2023 12:05:05 +1100
Subject: [PATCH 04/19] Update docs/handbook/image-file-formats.rst to fix lint

Co-authored-by: Andrew Murray <3112309+radarhere@users.noreply.github.com>
---
 docs/handbook/image-file-formats.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/docs/handbook/image-file-formats.rst b/docs/handbook/image-file-formats.rst
index 9128400ac..f466ccac8 100644
--- a/docs/handbook/image-file-formats.rst
+++ b/docs/handbook/image-file-formats.rst
@@ -590,13 +590,13 @@ The :py:meth:`~PIL.Image.Image.save` method supports the following options:
     .. versionadded:: 9.1.0
 
 **comment**
-    Adds a custom comment to the file, replacing the default 
+    Adds a custom comment to the file, replacing the default
     "Created by OpenJPEG version" comment.
 
     .. versionadded:: 9.5.0
 
 **add_plt**
-    If ``True`` then include a PLT (packet length, tile-part header) marker 
+    If ``True`` then include a PLT (packet length, tile-part header) marker
     segment in the produced file.
     The default is to not include it.
 

From b00bde977199968aa62c539b85ef3feb2338d080 Mon Sep 17 00:00:00 2001
From: Josh Ware <josh@joshw.info>
Date: Thu, 19 Jan 2023 22:52:41 +1100
Subject: [PATCH 05/19] Update Tests/test_file_jpeg2k.py fix spelling error

Co-authored-by: Andrew Murray <3112309+radarhere@users.noreply.github.com>
---
 Tests/test_file_jpeg2k.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index 6107075d5..ccc18772a 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -396,7 +396,7 @@ def test_plt_marker():
         while True:
             box_bytes = out.read(2)
             if len(box_bytes) == 0:
-                # End of steam encounterd and no PLT or SOD
+                # End of steam encountered and no PLT or SOD
                 break
             jp2_boxid = struct.unpack(">H", box_bytes)[0]
 

From 79e67cb5c33e5cef781e664439bc5c7371c1c04c Mon Sep 17 00:00:00 2001
From: Andrew Murray <3112309+radarhere@users.noreply.github.com>
Date: Tue, 31 Jan 2023 21:42:25 +1100
Subject: [PATCH 06/19] Removed default argument

---
 src/PIL/Jpeg2KImagePlugin.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/PIL/Jpeg2KImagePlugin.py b/src/PIL/Jpeg2KImagePlugin.py
index 001dcf39c..68a354e3f 100644
--- a/src/PIL/Jpeg2KImagePlugin.py
+++ b/src/PIL/Jpeg2KImagePlugin.py
@@ -328,7 +328,7 @@ def _save(im, fp, filename):
     mct = info.get("mct", 0)
     signed = info.get("signed", False)
     fd = -1
-    comment = info.get("comment", None)
+    comment = info.get("comment")
     add_plt = info.get("add_plt", False)
 
     if hasattr(fp, "fileno"):

From 18ad4c867ff8a53a6c40d6fdf954799b976ab7f0 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Tue, 31 Jan 2023 21:49:12 +1100
Subject: [PATCH 07/19] Use skip_unless_feature_version

---
 Tests/test_file_jpeg2k.py | 50 +++++++++++++++++++--------------------
 1 file changed, 24 insertions(+), 26 deletions(-)

diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index ccc18772a..5669af7ab 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -12,6 +12,7 @@ from .helper import (
     assert_image_similar,
     assert_image_similar_tofile,
     skip_unless_feature,
+    skip_unless_feature_version,
 )
 
 EXTRA_DIR = "Tests/images/jpeg2000"
@@ -384,34 +385,31 @@ def test_custom_comment():
     assert bytes(unique_comment, "utf-8") in data
 
 
+@skip_unless_feature_version("jpg_2000", "2.4.0")
 def test_plt_marker():
     # Search the start of the codesteam for the PLT box (id 0xFF58)
-    opj_version = re.search(r"(\d+\.\d+)\.\d+$", features.version_codec("jpg_2000"))
-    assert opj_version is not None
+    out = BytesIO()
+    test_card.save(out, "JPEG2000", no_jp2=True, add_plt=True)
+    out.seek(0)
+    while True:
+        box_bytes = out.read(2)
+        if len(box_bytes) == 0:
+            # End of steam encountered and no PLT or SOD
+            break
+        jp2_boxid = struct.unpack(">H", box_bytes)[0]
 
-    if float(opj_version[1]) >= 2.4:
-        out = BytesIO()
-        test_card.save(out, "JPEG2000", no_jp2=True, add_plt=True)
-        out.seek(0)
-        while True:
-            box_bytes = out.read(2)
-            if len(box_bytes) == 0:
-                # End of steam encountered and no PLT or SOD
-                break
-            jp2_boxid = struct.unpack(">H", box_bytes)[0]
+        if jp2_boxid == 0xFF4F:
+            # No length specifier for main header
+            continue
+        elif jp2_boxid == 0xFF58:
+            # This is the PLT box we're looking for
+            return
+        elif jp2_boxid == 0xFF93:
+            break
+            # SOD box encountered and no PLT, so it wasn't found
 
-            if jp2_boxid == 0xFF4F:
-                # No length specifier for main header
-                continue
-            elif jp2_boxid == 0xFF58:
-                # This is the PLT box we're looking for
-                return
-            elif jp2_boxid == 0xFF93:
-                break
-                # SOD box encountered and no PLT, so it wasn't found
+        jp2_boxlength = struct.unpack(">H", out.read(2))[0]
+        out.seek(jp2_boxlength - 2, os.SEEK_CUR)
 
-            jp2_boxlength = struct.unpack(">H", out.read(2))[0]
-            out.seek(jp2_boxlength - 2, os.SEEK_CUR)
-
-        # The PLT box wasn't found
-        raise ValueError
+    # The PLT box wasn't found
+    raise ValueError

From ca97e2a3a51fcad8eab4d5466b944e512b82dadd Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Tue, 31 Jan 2023 22:31:52 +1100
Subject: [PATCH 08/19] Use _binary

---
 Tests/test_file_jpeg2k.py | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index 5669af7ab..56d8a7974 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -1,11 +1,17 @@
 import os
 import re
-import struct
 from io import BytesIO
 
 import pytest
 
-from PIL import Image, ImageFile, Jpeg2KImagePlugin, UnidentifiedImageError, features
+from PIL import (
+    Image,
+    ImageFile,
+    Jpeg2KImagePlugin,
+    UnidentifiedImageError,
+    _binary,
+    features,
+)
 
 from .helper import (
     assert_image_equal,
@@ -393,11 +399,11 @@ def test_plt_marker():
     out.seek(0)
     while True:
         box_bytes = out.read(2)
-        if len(box_bytes) == 0:
+        if not box_bytes:
             # End of steam encountered and no PLT or SOD
             break
-        jp2_boxid = struct.unpack(">H", box_bytes)[0]
 
+        jp2_boxid = _binary.i16be(box_bytes)
         if jp2_boxid == 0xFF4F:
             # No length specifier for main header
             continue
@@ -405,10 +411,10 @@ def test_plt_marker():
             # This is the PLT box we're looking for
             return
         elif jp2_boxid == 0xFF93:
-            break
             # SOD box encountered and no PLT, so it wasn't found
+            break
 
-        jp2_boxlength = struct.unpack(">H", out.read(2))[0]
+        jp2_boxlength = _binary.i16be(out.read(2))
         out.seek(jp2_boxlength - 2, os.SEEK_CUR)
 
     # The PLT box wasn't found

From 4bb50b1fa7fe5ef4323b9cb0c819bfba2b608f7f Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Tue, 31 Jan 2023 22:24:47 +1100
Subject: [PATCH 09/19] Test comment too long

---
 Tests/test_file_jpeg2k.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index 56d8a7974..a0fb75016 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -390,6 +390,10 @@ def test_custom_comment():
     # Lazy method to determine if the comment is in the image generated
     assert bytes(unique_comment, "utf-8") in data
 
+    too_long_comment = " " * 65532
+    with pytest.raises(ValueError):
+        test_card.save(output_stream, "JPEG2000", comment=too_long_comment)
+
 
 @skip_unless_feature_version("jpg_2000", "2.4.0")
 def test_plt_marker():

From 04e8a9b3e723a867f220124c26489ace5d2187e0 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Tue, 31 Jan 2023 22:24:52 +1100
Subject: [PATCH 10/19] Removed unnecessary code

---
 src/encode.c            | 6 ++----
 src/libImaging/Jpeg2K.h | 2 +-
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/encode.c b/src/encode.c
index 33a2a37a7..e8946dbae 100644
--- a/src/encode.c
+++ b/src/encode.c
@@ -1214,7 +1214,7 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
     char mct = 0;
     int sgnd = 0;
     Py_ssize_t fd = -1;
-    char * comment = NULL;
+    char *comment = NULL;
     int add_plt = 0;
 
     if (!PyArg_ParseTuple(
@@ -1326,7 +1326,7 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
                 PyExc_ValueError,
                 "JPEG 2000 comment is too long");
             Py_DECREF(encoder);
-            return NULL;            
+            return NULL;
         }
 
         context->comment = strdup(comment);
@@ -1338,8 +1338,6 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
             Py_DECREF(encoder);
             return NULL;
         }
-    } else {
-        context->comment = NULL;
     }
 
     if (quality_layers && PySequence_Check(quality_layers)) {
diff --git a/src/libImaging/Jpeg2K.h b/src/libImaging/Jpeg2K.h
index 65728be5d..7bf8b4b0a 100644
--- a/src/libImaging/Jpeg2K.h
+++ b/src/libImaging/Jpeg2K.h
@@ -98,7 +98,7 @@ typedef struct {
     const char *error_msg;
 
     /* Custom comment */
-    char * comment;
+    char *comment;
 
     /* Include PLT marker segment */
     int add_plt;

From d3923f71420c58f8545fc74fc5f41f0b415635f8 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Thu, 23 Mar 2023 17:53:35 +1100
Subject: [PATCH 11/19] Use reading of comments to test saving comments

---
 Tests/test_file_jpeg2k.py | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index 8261c612a..a869d74f0 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -372,6 +372,20 @@ def test_comment():
             pass
 
 
+def test_save_comment():
+    comment = "Created by Pillow"
+    out = BytesIO()
+    test_card.save(out, "JPEG2000", comment=comment)
+    out.seek(0)
+
+    with Image.open(out) as im:
+        assert im.info["comment"] == b"Created by Pillow"
+
+    too_long_comment = " " * 65532
+    with pytest.raises(ValueError):
+        test_card.save(out, "JPEG2000", comment=too_long_comment)
+
+
 @pytest.mark.parametrize(
     "test_file",
     [
@@ -391,20 +405,6 @@ def test_crashes(test_file):
                 pass
 
 
-def test_custom_comment():
-    output_stream = BytesIO()
-    unique_comment = "This is a unique comment, which should be found below"
-    test_card.save(output_stream, "JPEG2000", comment=unique_comment)
-    output_stream.seek(0)
-    data = output_stream.read()
-    # Lazy method to determine if the comment is in the image generated
-    assert bytes(unique_comment, "utf-8") in data
-
-    too_long_comment = " " * 65532
-    with pytest.raises(ValueError):
-        test_card.save(output_stream, "JPEG2000", comment=too_long_comment)
-
-
 @skip_unless_feature_version("jpg_2000", "2.4.0")
 def test_plt_marker():
     # Search the start of the codesteam for the PLT box (id 0xFF58)

From 7c3fd254330ebcbd51fa08ef0b709b52587f5b92 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Fri, 24 Mar 2023 09:45:51 +1100
Subject: [PATCH 12/19] Allow saving bytes as comments

---
 Tests/test_file_jpeg2k.py    | 14 +++++++-------
 src/PIL/Jpeg2KImagePlugin.py |  4 +++-
 src/encode.c                 | 21 +++++++++++----------
 3 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index a869d74f0..60be50e07 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -373,15 +373,15 @@ def test_comment():
 
 
 def test_save_comment():
-    comment = "Created by Pillow"
-    out = BytesIO()
-    test_card.save(out, "JPEG2000", comment=comment)
-    out.seek(0)
+    for comment in ("Created by Pillow", b"Created by Pillow"):
+        out = BytesIO()
+        test_card.save(out, "JPEG2000", comment=comment)
+        out.seek(0)
 
-    with Image.open(out) as im:
-        assert im.info["comment"] == b"Created by Pillow"
+        with Image.open(out) as im:
+            assert im.info["comment"] == b"Created by Pillow"
 
-    too_long_comment = " " * 65532
+    too_long_comment = " " * 65531
     with pytest.raises(ValueError):
         test_card.save(out, "JPEG2000", comment=too_long_comment)
 
diff --git a/src/PIL/Jpeg2KImagePlugin.py b/src/PIL/Jpeg2KImagePlugin.py
index 4249fe714..980c299db 100644
--- a/src/PIL/Jpeg2KImagePlugin.py
+++ b/src/PIL/Jpeg2KImagePlugin.py
@@ -351,10 +351,12 @@ def _save(im, fp, filename):
     cinema_mode = info.get("cinema_mode", "no")
     mct = info.get("mct", 0)
     signed = info.get("signed", False)
-    fd = -1
     comment = info.get("comment")
+    if isinstance(comment, str):
+        comment = comment.encode()
     add_plt = info.get("add_plt", False)
 
+    fd = -1
     if hasattr(fp, "fileno"):
         try:
             fd = fp.fileno()
diff --git a/src/encode.c b/src/encode.c
index e8946dbae..7dcb79766 100644
--- a/src/encode.c
+++ b/src/encode.c
@@ -1215,11 +1215,12 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
     int sgnd = 0;
     Py_ssize_t fd = -1;
     char *comment = NULL;
+    Py_ssize_t comment_size;
     int add_plt = 0;
 
     if (!PyArg_ParseTuple(
             args,
-            "ss|OOOsOnOOOssbbnzp",
+            "ss|OOOsOnOOOssbbnz#p",
             &mode,
             &format,
             &offset,
@@ -1237,6 +1238,7 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
             &sgnd,
             &fd,
             &comment,
+            &comment_size,
             &add_plt)) {
         return NULL;
     }
@@ -1319,9 +1321,9 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
         }
     }
 
-    if (comment != NULL && strlen(comment) > 0) {
+    if (comment && comment_size > 0) {
         /* Size is stored as as an uint16, subtract 4 bytes for the header */
-        if (strlen(comment) >= 65531) {
+        if (comment_size >= 65531) {
             PyErr_SetString(
                 PyExc_ValueError,
                 "JPEG 2000 comment is too long");
@@ -1329,15 +1331,14 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
             return NULL;
         }
 
-        context->comment = strdup(comment);
-
-        if (context->comment == NULL) {
-            PyErr_SetString(
-                PyExc_MemoryError,
-                "Couldn't allocate memory for JPEG 2000 comment");
+        char *p = malloc(comment_size + 1);
+        if (!p) {
             Py_DECREF(encoder);
-            return NULL;
+            return ImagingError_MemoryError();
         }
+        memcpy(p, comment, comment_size);
+        p[comment_size] = '\0';
+        context->comment = p;
     }
 
     if (quality_layers && PySequence_Check(quality_layers)) {

From 1fd189164c8905d2f99f0d9836ef7ea4c897b055 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Mon, 27 Mar 2023 22:38:29 +1100
Subject: [PATCH 13/19] Renamed "add_plt" to "plt"

---
 Tests/test_file_jpeg2k.py     | 2 +-
 src/PIL/Jpeg2KImagePlugin.py  | 4 ++--
 src/encode.c                  | 6 +++---
 src/libImaging/Jpeg2K.h       | 2 +-
 src/libImaging/Jpeg2KEncode.c | 2 +-
 5 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index 60be50e07..7b512695b 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -409,7 +409,7 @@ def test_crashes(test_file):
 def test_plt_marker():
     # Search the start of the codesteam for the PLT box (id 0xFF58)
     out = BytesIO()
-    test_card.save(out, "JPEG2000", no_jp2=True, add_plt=True)
+    test_card.save(out, "JPEG2000", no_jp2=True, plt=True)
     out.seek(0)
     while True:
         box_bytes = out.read(2)
diff --git a/src/PIL/Jpeg2KImagePlugin.py b/src/PIL/Jpeg2KImagePlugin.py
index 980c299db..e7d91c818 100644
--- a/src/PIL/Jpeg2KImagePlugin.py
+++ b/src/PIL/Jpeg2KImagePlugin.py
@@ -354,7 +354,7 @@ def _save(im, fp, filename):
     comment = info.get("comment")
     if isinstance(comment, str):
         comment = comment.encode()
-    add_plt = info.get("add_plt", False)
+    plt = info.get("plt", False)
 
     fd = -1
     if hasattr(fp, "fileno"):
@@ -379,7 +379,7 @@ def _save(im, fp, filename):
         signed,
         fd,
         comment,
-        add_plt,
+        plt,
     )
 
     ImageFile._save(im, fp, [("jpeg2k", (0, 0) + im.size, 0, kind)])
diff --git a/src/encode.c b/src/encode.c
index 7dcb79766..8aa357b6c 100644
--- a/src/encode.c
+++ b/src/encode.c
@@ -1216,7 +1216,7 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
     Py_ssize_t fd = -1;
     char *comment = NULL;
     Py_ssize_t comment_size;
-    int add_plt = 0;
+    int plt = 0;
 
     if (!PyArg_ParseTuple(
             args,
@@ -1239,7 +1239,7 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
             &fd,
             &comment,
             &comment_size,
-            &add_plt)) {
+            &plt)) {
         return NULL;
     }
 
@@ -1358,7 +1358,7 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
     context->cinema_mode = cine_mode;
     context->mct = mct;
     context->sgnd = sgnd;
-    context->add_plt = add_plt;
+    context->plt = plt;
 
     return (PyObject *)encoder;
 }
diff --git a/src/libImaging/Jpeg2K.h b/src/libImaging/Jpeg2K.h
index 7bf8b4b0a..e8d92f7b6 100644
--- a/src/libImaging/Jpeg2K.h
+++ b/src/libImaging/Jpeg2K.h
@@ -101,7 +101,7 @@ typedef struct {
     char *comment;
 
     /* Include PLT marker segment */
-    int add_plt;
+    int plt;
 
 } JPEG2KENCODESTATE;
 
diff --git a/src/libImaging/Jpeg2KEncode.c b/src/libImaging/Jpeg2KEncode.c
index 6d6add76e..a7c644197 100644
--- a/src/libImaging/Jpeg2KEncode.c
+++ b/src/libImaging/Jpeg2KEncode.c
@@ -502,7 +502,7 @@ j2k_encode_entry(Imaging im, ImagingCodecState state) {
 
     /* Enabling PLT markers only supported in OpenJPEG 2.4.0 and up */
 #if ((OPJ_VERSION_MAJOR == 2 && OPJ_VERSION_MINOR >= 4) || OPJ_VERSION_MAJOR > 2)
-    if (context->add_plt) {
+    if (context->plt) {
         const char * plt_option[2] = {"PLT=YES", NULL};
         opj_encoder_set_extra_options(codec, plt_option);
     }

From a7df096d1b03d53c9834989e3e2e5e4fb8b37f4e Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Mon, 27 Mar 2023 22:39:01 +1100
Subject: [PATCH 14/19] Added release notes

---
 docs/releasenotes/9.5.0.rst | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/docs/releasenotes/9.5.0.rst b/docs/releasenotes/9.5.0.rst
index 074931671..20d7ee893 100644
--- a/docs/releasenotes/9.5.0.rst
+++ b/docs/releasenotes/9.5.0.rst
@@ -48,11 +48,16 @@ Added ``corners`` argument to ``ImageDraw.rounded_rectangle()``
 ``corners``. This a tuple of Booleans, specifying whether to round each corner,
 ``(top_left, top_right, bottom_right, bottom_left)``.
 
-Reading JPEG comments
-^^^^^^^^^^^^^^^^^^^^^
+JPEG2000 comments and PLT marker
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 When opening a JPEG2000 image, the comment may now be read into
-:py:attr:`~PIL.Image.Image.info`.
+:py:attr:`~PIL.Image.Image.info`. The ``comment`` keyword argument can be used
+to save it back again.
+
+If OpenJPEG 2.4.0 or later is available and the ``plt`` keyword argument
+is present and true when saving JPEG2000 images, tell the encoder to generate
+PLT markers.
 
 Security
 ========

From 7d6ff23e1f493147057f062f95954b21e9eec0fb Mon Sep 17 00:00:00 2001
From: Andrew Murray <3112309+radarhere@users.noreply.github.com>
Date: Tue, 28 Mar 2023 07:32:30 +1100
Subject: [PATCH 15/19] Renamed "add_plt" to "plt"

Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>
---
 docs/handbook/image-file-formats.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/handbook/image-file-formats.rst b/docs/handbook/image-file-formats.rst
index 11380cd55..de6b79371 100644
--- a/docs/handbook/image-file-formats.rst
+++ b/docs/handbook/image-file-formats.rst
@@ -595,7 +595,7 @@ The :py:meth:`~PIL.Image.Image.save` method supports the following options:
 
     .. versionadded:: 9.5.0
 
-**add_plt**
+**plt**
     If ``True`` then include a PLT (packet length, tile-part header) marker
     segment in the produced file.
     The default is to not include it.

From 598216fb465682646a307b930047d56adb0a42b7 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Wed, 29 Mar 2023 19:18:50 +1100
Subject: [PATCH 16/19] OpenJPEG 2.4.0 or later is required for PLT markers

---
 docs/handbook/image-file-formats.rst | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/docs/handbook/image-file-formats.rst b/docs/handbook/image-file-formats.rst
index de6b79371..74ba883b1 100644
--- a/docs/handbook/image-file-formats.rst
+++ b/docs/handbook/image-file-formats.rst
@@ -596,9 +596,9 @@ The :py:meth:`~PIL.Image.Image.save` method supports the following options:
     .. versionadded:: 9.5.0
 
 **plt**
-    If ``True`` then include a PLT (packet length, tile-part header) marker
-    segment in the produced file.
-    The default is to not include it.
+    If ``True`` and OpenJPEG 2.4.0 or later is available, then include a PLT
+    (packet length, tile-part header) marker in the produced file.
+    Defaults to ``False``.
 
     .. versionadded:: 9.5.0
 

From 2f66d2d6a1dd307e8c28ddc5f98707acc5874cdb Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Wed, 29 Mar 2023 19:19:05 +1100
Subject: [PATCH 17/19] Changed maximum comment length to 65531

---
 Tests/test_file_jpeg2k.py     | 10 +++++++---
 src/encode.c                  |  4 ++--
 src/libImaging/Jpeg2KEncode.c |  2 +-
 3 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index 7b512695b..b9422c76a 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -376,14 +376,18 @@ def test_save_comment():
     for comment in ("Created by Pillow", b"Created by Pillow"):
         out = BytesIO()
         test_card.save(out, "JPEG2000", comment=comment)
-        out.seek(0)
 
         with Image.open(out) as im:
             assert im.info["comment"] == b"Created by Pillow"
 
-    too_long_comment = " " * 65531
+    out = BytesIO()
+    long_comment = b" " * 65531
+    test_card.save(out, "JPEG2000", comment=long_comment)
+    with Image.open(out) as im:
+        assert im.info["comment"] == long_comment
+
     with pytest.raises(ValueError):
-        test_card.save(out, "JPEG2000", comment=too_long_comment)
+        test_card.save(out, "JPEG2000", comment=long_comment + b" ")
 
 
 @pytest.mark.parametrize(
diff --git a/src/encode.c b/src/encode.c
index 8aa357b6c..a66594935 100644
--- a/src/encode.c
+++ b/src/encode.c
@@ -1214,7 +1214,7 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
     char mct = 0;
     int sgnd = 0;
     Py_ssize_t fd = -1;
-    char *comment = NULL;
+    char *comment;
     Py_ssize_t comment_size;
     int plt = 0;
 
@@ -1323,7 +1323,7 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args) {
 
     if (comment && comment_size > 0) {
         /* Size is stored as as an uint16, subtract 4 bytes for the header */
-        if (comment_size >= 65531) {
+        if (comment_size >= 65532) {
             PyErr_SetString(
                 PyExc_ValueError,
                 "JPEG 2000 comment is too long");
diff --git a/src/libImaging/Jpeg2KEncode.c b/src/libImaging/Jpeg2KEncode.c
index a7c644197..8f6370061 100644
--- a/src/libImaging/Jpeg2KEncode.c
+++ b/src/libImaging/Jpeg2KEncode.c
@@ -503,7 +503,7 @@ j2k_encode_entry(Imaging im, ImagingCodecState state) {
     /* Enabling PLT markers only supported in OpenJPEG 2.4.0 and up */
 #if ((OPJ_VERSION_MAJOR == 2 && OPJ_VERSION_MINOR >= 4) || OPJ_VERSION_MAJOR > 2)
     if (context->plt) {
-        const char * plt_option[2] = {"PLT=YES", NULL};
+        const char *plt_option[2] = {"PLT=YES", NULL};
         opj_encoder_set_extra_options(codec, plt_option);
     }
 #endif

From 9a7a4482195125f38c668df3555043e8d3251da0 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Wed, 29 Mar 2023 20:14:29 +1100
Subject: [PATCH 18/19] Increase similiarity between test_plt_marker and
 _parse_comment

---
 Tests/test_file_jpeg2k.py    | 21 +++++++++++----------
 src/PIL/Jpeg2KImagePlugin.py |  8 ++++----
 2 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index b9422c76a..52e9f8853 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -411,29 +411,30 @@ def test_crashes(test_file):
 
 @skip_unless_feature_version("jpg_2000", "2.4.0")
 def test_plt_marker():
-    # Search the start of the codesteam for the PLT box (id 0xFF58)
+    # Search the start of the codesteam for PLT
     out = BytesIO()
     test_card.save(out, "JPEG2000", no_jp2=True, plt=True)
     out.seek(0)
     while True:
-        box_bytes = out.read(2)
-        if not box_bytes:
+        marker = out.read(2)
+        if not marker:
             # End of steam encountered and no PLT or SOD
             break
 
-        jp2_boxid = _binary.i16be(box_bytes)
+        jp2_boxid = _binary.i16be(marker)
         if jp2_boxid == 0xFF4F:
-            # No length specifier for main header
+            # SOC has no length
             continue
         elif jp2_boxid == 0xFF58:
-            # This is the PLT box we're looking for
+            # PLT
             return
         elif jp2_boxid == 0xFF93:
-            # SOD box encountered and no PLT, so it wasn't found
+            # SOD without finding PLT first
             break
 
-        jp2_boxlength = _binary.i16be(out.read(2))
-        out.seek(jp2_boxlength - 2, os.SEEK_CUR)
+        hdr = out.read(2)
+        length = _binary.i16be(hdr)
+        out.seek(length - 2, os.SEEK_CUR)
 
-    # The PLT box wasn't found
+    # PLT wasn't found
     raise ValueError
diff --git a/src/PIL/Jpeg2KImagePlugin.py b/src/PIL/Jpeg2KImagePlugin.py
index e7d91c818..9309768ba 100644
--- a/src/PIL/Jpeg2KImagePlugin.py
+++ b/src/PIL/Jpeg2KImagePlugin.py
@@ -17,7 +17,7 @@ import io
 import os
 import struct
 
-from . import Image, ImageFile
+from . import Image, ImageFile, _binary
 
 
 class BoxReader:
@@ -99,7 +99,7 @@ def _parse_codestream(fp):
     count from the SIZ marker segment, returning a PIL (size, mode) tuple."""
 
     hdr = fp.read(2)
-    lsiz = struct.unpack(">H", hdr)[0]
+    lsiz = _binary.i16be(hdr)
     siz = hdr + fp.read(lsiz - 2)
     lsiz, rsiz, xsiz, ysiz, xosiz, yosiz, _, _, _, _, csiz = struct.unpack_from(
         ">HHIIIIIIIIH", siz
@@ -258,7 +258,7 @@ class Jpeg2KImageFile(ImageFile.ImageFile):
 
     def _parse_comment(self):
         hdr = self.fp.read(2)
-        length = struct.unpack(">H", hdr)[0]
+        length = _binary.i16be(hdr)
         self.fp.seek(length - 2, os.SEEK_CUR)
 
         while True:
@@ -270,7 +270,7 @@ class Jpeg2KImageFile(ImageFile.ImageFile):
                 # Start of tile or end of codestream
                 break
             hdr = self.fp.read(2)
-            length = struct.unpack(">H", hdr)[0]
+            length = _binary.i16be(hdr)
             if typ == 0x64:
                 # Comment
                 self.info["comment"] = self.fp.read(length - 2)[2:]

From 6d3c1985e07dfa28ae14de5bf36c711bdfc9176d Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Wed, 29 Mar 2023 22:18:14 +1100
Subject: [PATCH 19/19] Assert false instead of raising an error

---
 Tests/test_file_jpeg2k.py | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index 52e9f8853..b6e8215f7 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -418,8 +418,7 @@ def test_plt_marker():
     while True:
         marker = out.read(2)
         if not marker:
-            # End of steam encountered and no PLT or SOD
-            break
+            assert False, "End of stream without PLT"
 
         jp2_boxid = _binary.i16be(marker)
         if jp2_boxid == 0xFF4F:
@@ -429,12 +428,8 @@ def test_plt_marker():
             # PLT
             return
         elif jp2_boxid == 0xFF93:
-            # SOD without finding PLT first
-            break
+            assert False, "SOD without finding PLT first"
 
         hdr = out.read(2)
         length = _binary.i16be(hdr)
         out.seek(length - 2, os.SEEK_CUR)
-
-    # PLT wasn't found
-    raise ValueError