ImageField is nullified after save

[lmanzurv]

When I fetch a document with an ImageField, the image can be read using doc.image.read(), but if I do a doc.save() and then I do a doc.image.read(), the image is empty

[jcodebrain]

Same Issue here : #1387

[jcodebrain]

same issue here

[bagerard]

I believe the problem is not the .save() but the .read(). As it's a file-like object, when you call .read() you are moving the cursor to the end of the file. If you then call .read() without "rewinding" it, you get None because there is nothing to read anymore. This is also the case with the underlying pymongo GridFS/GridOut structure so its not really a bug, you need to call .seek(0) if you want to read() it multiple times. The doc was improved to reflect this in #2229