[1.8.x] Fixed #24948 -- Fixed crash when uploading bitmap images in forms.ImageField

Backport of cf6ce279c7671a4c83c960c5c526f92679a4fac8 from master

2 files changed, 21 insertions, 0 deletions

diff --git a/tests/forms_tests/tests/filepath_test_files/1x1.bmp b/tests/forms_tests/tests/filepath_test_files/1x1.bmp
new file mode 100644
index 0000000000..021d5fa928
--- /dev/null
+++ b/tests/forms_tests/tests/filepath_test_files/1x1.bmp
diff --git a/tests/forms_tests/tests/test_fields.py b/tests/forms_tests/tests/test_fields.py
index 1d09b1a8b3..b082701c11 100644
--- a/tests/forms_tests/tests/test_fields.py
+++ b/tests/forms_tests/tests/test_fields.py
@@ -806,6 +806,26 @@ class FieldsTests(SimpleTestCase):
         self.assertEqual('PNG', uploaded_file.image.format)
         self.assertEqual('image/png', uploaded_file.content_type)
 
+    @skipIf(Image is None, "Pillow is required to test ImageField")
+    def test_imagefield_annotate_with_bitmap_image_after_clean(self):
+        """
+        This also tests the situation when Pillow doesn't detect the MIME type
+        of the image (#24948).
+        """
+        f = ImageField()
+
+        img_path = os.path.dirname(upath(__file__)) + '/filepath_test_files/1x1.bmp'
+        with open(img_path, 'rb') as img_file:
+            img_data = img_file.read()
+
+        img_file = SimpleUploadedFile('1x1.bmp', img_data)
+        img_file.content_type = 'text/plain'
+
+        uploaded_file = f.clean(img_file)
+
+        self.assertEqual('BMP', uploaded_file.image.format)
+        self.assertIsNone(uploaded_file.content_type)
+
     # URLField ##################################################################
 
     def test_urlfield_1(self):
@@ -1347,6 +1367,7 @@ class FieldsTests(SimpleTestCase):
         f.choices.sort()
         expected = [
             ('/tests/forms_tests/tests/filepath_test_files/.dot-file', '.dot-file'),
+            ('/tests/forms_tests/tests/filepath_test_files/1x1.bmp', '1x1.bmp'),
             ('/tests/forms_tests/tests/filepath_test_files/1x1.png', '1x1.png'),
             ('/tests/forms_tests/tests/filepath_test_files/directory', 'directory'),
             ('/tests/forms_tests/tests/filepath_test_files/fake-image.jpg', 'fake-image.jpg'),