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

Backport of cf6ce279c7671a4c83c960c5c526f92679a4fac8 from master

1 files changed, 8 insertions, 5 deletions

diff --git a/docs/ref/forms/fields.txt b/docs/ref/forms/fields.txt
index c8317924d9..55a8bc049e 100644
--- a/docs/ref/forms/fields.txt
+++ b/docs/ref/forms/fields.txt
@@ -690,13 +690,16 @@ For each field, we describe the default widget used if you don't specify
     When you use an ``ImageField`` on a form, you must also remember to
     :ref:`bind the file data to the form <binding-uploaded-files>`.
 
+    After the field has been cleaned and validated, the ``UploadedFile``
+    object will have an additional ``image`` attribute containing the Pillow
+    `Image`_ instance used to check if the file was a valid image. Also,
+    ``UploadedFile.content_type`` will be updated with the image's content type
+    if Pillow can determine it, otherwise it will be set to ``None``.
+
     .. versionchanged:: 1.8
 
-        After the field has been cleaned and validated, the ``UploadedFile``
-        object will have an additional ``image`` attribute containing the Pillow
-        `Image`_ instance used to check if the file was a valid image.
-        ``UploadedFile.content_type`` is also updated with the image's content
-        type as determined by Pillow.
+        The ``image`` and ``content_type`` attributes described in the last
+        paragraph were added.
 
 .. _Pillow: http://pillow.readthedocs.org/en/latest/
 .. _Image: https://pillow.readthedocs.org/en/latest/reference/Image.html