From bcacc6321ae819965f478bfee2072a796801f298 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fran=C3=A7ois=20Freitag?= Date: Sat, 17 Jun 2023 18:00:43 +0200 Subject: [PATCH] Refs #34517 -- Restored skipping ImageFileField.update_dimension_fields without width/height fields. This avoids reading the image size when the dimensions fields (image_width, image_height) do not exist, as that operation may be expensive. Partially reverts ea53e7c09f1b8864c20c65976bbeaeab77abdaec, that dropped the check for the dimension fields in update_dimension_fields(), because the post_init signal was no longer registered without dimension fields. However, another code path to that function exists: when the ImageFileField is save()d, the name from the storage is setattr()ed on the field, and ImageFileDescriptor calls update_dimension_fields() because the image size might have changed. Keep bailing out early when dimensions are unused. Besides, computing the image dimensions causes to close() the file, resulting in a backward-incompatible change. The test protects against that change. --- django/db/models/fields/files.py | 6 ++++-- tests/model_fields/test_imagefield.py | 7 +++++++ 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/django/db/models/fields/files.py b/django/db/models/fields/files.py index e10c8cd69a..95985684ee 100644 --- a/django/db/models/fields/files.py +++ b/django/db/models/fields/files.py @@ -458,8 +458,10 @@ class ImageField(FileField): Dimensions can be forced to update with force=True, which is how ImageFileDescriptor.__set__ calls this method. """ - # Nothing to update if the field is deferred. - if self.attname not in instance.__dict__: + # Nothing to update if the field doesn't have dimension fields or if + # the field is deferred. + has_dimension_fields = self.width_field or self.height_field + if not has_dimension_fields or self.attname not in instance.__dict__: return # getattr will call the ImageFileDescriptor's __get__ method, which diff --git a/tests/model_fields/test_imagefield.py b/tests/model_fields/test_imagefield.py index 81ac9dad61..8bbfee30f2 100644 --- a/tests/model_fields/test_imagefield.py +++ b/tests/model_fields/test_imagefield.py @@ -336,6 +336,13 @@ class ImageFieldNoDimensionsTests(ImageFieldTwoDimensionsTests): [sender_id for (_, sender_id), *_ in signals.post_init.receivers], ) + def test_save_does_not_close_file(self): + p = self.PersonModel(name="Joe") + p.mugshot.save("mug", self.file1) + with p.mugshot as f: + # Underlying file object wasn’t closed. + self.assertEqual(f.tell(), 0) + @skipIf(Image is None, "Pillow is required to test ImageField") class ImageFieldOneDimensionTests(ImageFieldTwoDimensionsTests):