From 3c185d1f696dfbe20a5401a2f36edd392b2094d2 Mon Sep 17 00:00:00 2001 From: Andrew Murray <3112309+radarhere@users.noreply.github.com> Date: Thu, 27 Mar 2025 23:44:27 +1100 Subject: [PATCH] Do not load image during save if file extension is unknown (#8835) Co-authored-by: Andrew Murray --- Tests/test_file_hdf5stub.py | 2 +- src/PIL/Image.py | 14 +++++++------- 2 files changed, 8 insertions(+), 8 deletions(-) diff --git a/Tests/test_file_hdf5stub.py b/Tests/test_file_hdf5stub.py index 50864009f..e4f09a09c 100644 --- a/Tests/test_file_hdf5stub.py +++ b/Tests/test_file_hdf5stub.py @@ -43,7 +43,7 @@ def test_save() -> None: # Arrange with Image.open(TEST_FILE) as im: dummy_fp = BytesIO() - dummy_filename = "dummy.filename" + dummy_filename = "dummy.h5" # Act / Assert: stub cannot save without an implemented handler with pytest.raises(OSError): diff --git a/src/PIL/Image.py b/src/PIL/Image.py index e2a76dfe1..d338e4dfd 100644 --- a/src/PIL/Image.py +++ b/src/PIL/Image.py @@ -2510,13 +2510,6 @@ class Image: # only set the name for metadata purposes filename = os.fspath(fp.name) - # may mutate self! - self._ensure_mutable() - - save_all = params.pop("save_all", False) - self.encoderinfo = {**getattr(self, "encoderinfo", {}), **params} - self.encoderconfig: tuple[Any, ...] = () - preinit() filename_ext = os.path.splitext(filename)[1].lower() @@ -2531,6 +2524,13 @@ class Image: msg = f"unknown file extension: {ext}" raise ValueError(msg) from e + # may mutate self! + self._ensure_mutable() + + save_all = params.pop("save_all", False) + self.encoderinfo = {**getattr(self, "encoderinfo", {}), **params} + self.encoderconfig: tuple[Any, ...] = () + if format.upper() not in SAVE: init() if save_all: