Browser validations break save on persisted objects with images

[tagliala]

Let's say we have a model with an image

class Player < ActiveRecord::Base
  mount_uploader :image, ImageUploader

  validates :name, presence: true
  validates :image, presence: true
end

Saving a new object or editing the image is fine

but when you try to save a persisted model without editing the image, you get a validation error on the file upload field

Refers to #2339 #2373

[mshibuya]

Merged #2373.

[tagliala]

btw this is still an issue with browser validations activated (default behaviour)

This should be reopened

[mshibuya]

Fixed now, thanks!

[dalpo]

👍 Thanks!

[tagliala]

thanks and sorry for not submitting a PR myself