Add typing information to ImageCmsProfile, and deprecate product_name/product_info

The _set method is no longer necessary, since we no longer compute any
attributes from the profile. In most cases, we only set the profile, and
in only one branch do we set the filename to anything non-None.

product_name/product_info were set to None at some point during what
appears to be a batch of changes for Python 3 compatibility
(ce041fd199), and never set back. Given
this, let's deprecate these and schedule them for removal in Pillow 13.

docs/deprecations.rst

@@ -193,6 +193,29 @@ Image.Image.get_child_images()
 method uses an image's file pointer, and so child images could only be retrieved from
 an :py:class:`PIL.ImageFile.ImageFile` instance.
 
+ImageCms.ImageCmsProfile._set
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. deprecated:: 11.3.0
+
+``ImageCms.ImageCmsProfile._set()`` has been deprecated, and will be removed in
+Pillow 13 (2026-10-15). You should construct a new ``ImageCmsProfile`` instance
+instead.
+
+ImageCms.ImageCmsProfile.product_name and .product_info
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. deprecated:: 11.3.0
+
+``ImageCms.ImageCmsProfile.product_name`` and the corresponding
+``.product_info`` attributes have been deprecated, and will be removed in
+Pillow 13 (2026-10-15). These attributes can be accessed on the ``.profile``
+attribute of ``ImageCmsProfile`` instead.
+
+Note that ``.product_name`` and ``.product_info`` have been set to ``None`` on
+``ImageCmsProfile`` since Pillow 2.3.0 (2014-01-01), so any working code that
+makes use of this data will already access it on ``.profile``.
+
 Removed features
 ----------------
 

src/PIL/ImageCms.py

@@ -241,6 +241,9 @@ _FLAGS = {
 
 
 class ImageCmsProfile:
+    profile: core.CmsProfile
+    filename: str | None
+
     def __init__(self, profile: str | SupportsRead[bytes] | core.CmsProfile) -> None:
         """
         :param profile: Either a string representing a filename,
@@ -248,6 +251,7 @@ class ImageCmsProfile:
             low-level profile object
 
         """
+        self.filename = None
 
         if isinstance(profile, str):
             if sys.platform == "win32":
@@ -256,22 +260,40 @@ class ImageCmsProfile:
                     profile_bytes_path.decode("ascii")
                 except UnicodeDecodeError:
                     with open(profile, "rb") as f:
-                        self._set(core.profile_frombytes(f.read()))
+                        self.profile = core.profile_frombytes(f.read())
                     return
-            self._set(core.profile_open(profile), profile)
+            self.filename = profile
+            self.profile = core.profile_open(profile)
         elif hasattr(profile, "read"):
-            self._set(core.profile_frombytes(profile.read()))
+            self.profile = core.profile_frombytes(profile.read())
         elif isinstance(profile, core.CmsProfile):
-            self._set(profile)
+            self.profile = profile
         else:
             msg = "Invalid type for Profile"  # type: ignore[unreachable]
             raise TypeError(msg)
 
+    def __getattr__(self, attr: str) -> Any:
+        if attr in ("product_name", "product_info"):
+            deprecate(
+                f"ImageCms.ImageCmsProfile.{attr}",
+                13,
+                action=(
+                    f"Use ImageCms.ImageCmsProfile.profile.{attr} instead. "
+                    f"Note that {attr} has been set to 'None' since Pillow 2.3.0."
+                ),
+            )
+            return None
+        msg = f"'{self.__class__.__name__}' has no attribute '{attr}'"
+        raise AttributeError(msg)
+
     def _set(self, profile: core.CmsProfile, filename: str | None = None) -> None:
+        deprecate(
+            "ImageCmsProfile._set",
+            13,
+            action="Set the 'profile' and 'filename' attributes directly instead.",
+        )
         self.profile = profile
         self.filename = filename
-        self.product_name = None  # profile.product_name
-        self.product_info = None  # profile.product_info
 
     def tobytes(self) -> bytes:
         """