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Do not assign new fp attribute when exiting context manager #7566

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Merged
hugovk merged 2 commits into from
Dec 31, 2023
Merged

Do not assign new fp attribute when exiting context manager #7566

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5431b15
Do not assign new fp attribute to image when exiting context manager
radarhere Nov 24, 2023
5fb86c5
Moved code closing fp and _fp into common method
radarhere Nov 29, 2023
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5 changes: 5 additions & 0 deletions Tests/test_image.py
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Original file line number Diff line number Diff line change
Expand Up @@ -1015,6 +1015,11 @@ def test_fli_overrun2(self):
except OSError as e:
assert str(e) == "buffer overrun when reading image file"

def test_exit_fp(self):
with Image.new("L", (1, 1)) as im:
pass
assert not hasattr(im, "fp")

def test_close_graceful(self, caplog):
with Image.open("Tests/images/hopper.jpg") as im:
copy = im.copy()
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17 changes: 9 additions & 8 deletions src/PIL/Image.py
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Original file line number Diff line number Diff line change
Expand Up @@ -528,14 +528,15 @@ def __enter__(self):
return self

def __exit__(self, *args):
if hasattr(self, "fp") and getattr(self, "_exclusive_fp", False):
if getattr(self, "_fp", False):
if self._fp != self.fp:
self._fp.close()
self._fp = DeferredError(ValueError("Operation on closed image"))
if self.fp:
self.fp.close()
self.fp = None
if hasattr(self, "fp"):
if getattr(self, "_exclusive_fp", False):
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@akx akx Nov 29, 2023

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Out of curiosity: does exclusive_fp mean, like I think it does, "we own this fp because we opened it"? If so, does it make sense for .close() to also close FPs that aren't "owned" by this instance?

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@radarhere radarhere Nov 29, 2023

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Out of curiosity: does exclusive_fp mean, like I think it does, "we own this fp because we opened it"?

Yes

Pillow/src/PIL/Image.py

Lines 3250 to 3258 in 697c24b

if filename:
fp = builtins.open(filename, "rb")
exclusive_fp = True
try:
fp.seek(0)
except (AttributeError, io.UnsupportedOperation):
fp = io.BytesIO(fp.read())
exclusive_fp = True

If so, does it make sense for .close() to also close FPs that aren't "owned" by this instance?

See #5309

if getattr(self, "_fp", False):
if self._fp != self.fp:
self._fp.close()
self._fp = DeferredError(ValueError("Operation on closed image"))
if self.fp:
self.fp.close()
self.fp = None
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@akx akx Nov 29, 2023

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Might be easier to read if the outermost layer of the pyramid was negated?

Suggested change
if hasattr(self, "fp"):
if getattr(self, "_exclusive_fp", False):
if getattr(self, "_fp", False):
if self._fp != self.fp:
self._fp.close()
self._fp = DeferredError(ValueError("Operation on closed image"))
if self.fp:
self.fp.close()
self.fp = None
if not hasattr(self, "fp"):
return
if getattr(self, "_exclusive_fp", False):
if getattr(self, "_fp", False):
if self._fp != self.fp:
self._fp.close()
self._fp = DeferredError(ValueError("Operation on closed image"))
if self.fp:
self.fp.close()
self.fp = None

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@radarhere radarhere Nov 29, 2023

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Easier to read in isolation, yes, but I kind of like the fact that this version mirrors close() -

Pillow/src/PIL/Image.py

Lines 530 to 565 in 5431b15

def __exit__(self, *args):
if hasattr(self, "fp"):
if getattr(self, "_exclusive_fp", False):
if getattr(self, "_fp", False):
if self._fp != self.fp:
self._fp.close()
self._fp = DeferredError(ValueError("Operation on closed image"))
if self.fp:
self.fp.close()
self.fp = None
def close(self):
"""
Closes the file pointer, if possible.
This operation will destroy the image core and release its memory.
The image data will be unusable afterward.
This function is required to close images that have multiple frames or
have not had their file read and closed by the
:py:meth:`~PIL.Image.Image.load` method. See :ref:`file-handling` for
more information.
"""
if hasattr(self, "fp"):
try:
if getattr(self, "_fp", False):
if self._fp != self.fp:
self._fp.close()
self._fp = DeferredError(ValueError("Operation on closed image"))
if self.fp:
self.fp.close()
self.fp = None
except Exception as msg:
logger.debug("Error closing: %s", msg)
if getattr(self, "map", None):

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@akx akx Nov 29, 2023

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Should that code be extracted from close() then and reused in both of these places? _close_fp()?

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@radarhere radarhere Nov 29, 2023

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Ok, I've pushed a commit.


def close(self):
"""
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