Image uploads fail

Correction:

Actually, Plupload 7.x-2.x-dev and 7.x-1.7 behave differently.

• The procedure described above (upload files a 2nd time, plupload discards one file of the batch) applies only to 7.x-1.7.
• Plupload 7.x-2.x-dev makes it completely impossible to upload image files. Though, still the same error message

I reverted back to Plupload 7.x-1.7 and the dated library in version 1.5.8 which gives me the described behaviour: first upload attempt - error message - second upload attempt - files are uploaded, but one from the batch is discarded.

Most probably It won't make It work, but wanted to clarify that 7.x-2.x-dev expects a diferent version of plupload library, probably something around 2.1 or 2.3.

In combination with plupload-7.x-2.x-dev, I used 'Plupload 2.3.9 AGPLv3' (from https://github.com/moxiecode/plupload/archive/v2.3.9.zip). According to ./admin/reports/status, the plupload module seems to have been happy with it (Status Report complained in combo with 1.5.8).

However, I noticed that ./admin/reports/libraries lists the libraries (both versions) as "Unregistered" (= "These libraries were found in the filesystem but there is no metadata about them", opposed to "Installed" = "These libraries are registered and installed correctly". I have no idea if that "Installed" vs. "Unregistered" status is merely cosmetic or has any functional impact, but I doubt that it is relevant to the file upload issue I am encountering (unless that is handled more strict since Drupal core 7.99).

This is the change in core that makes plupload fail since 7.99 -> https://www.drupal.org/node/2345695 →

The removal of this line in modules/image/image.field.inc works around the issue:

$elements[$delta]['#upload_validators']['file_validate_is_image'] = array();

The commit -> https://git.drupalcode.org/project/drupal/-/commit/fd71fedd655b76e3652fc...

Now we just need a proper fix :)

@budalokko: Thank you!

I removed this line of code in ./modules/image/image.field.inc, and the error is fully gone. No more bogus error messages, no more silently discarded image files. Excellent!

This applies to Plupload module 7.x-1.7 and the library in version 1.5.8.

Regarding that Drupal core issue #2345695 with status "Closed (fixed)", it simply introduced a regression affecting real data by attempting to fix a nothingburger about a fringe case. Since the broken validation routine is in Drupal core, Plupload module can not fix it or work around it, right?

a possible workaround without patching core:

function my_custom_module__field_widget_form_alter(&$element, &$form_state, $context) {
  if ($context['field']['type'] == 'image') {
    foreach ($element as $delta => $child) {
      if (isset($child['#upload_validators']['file_validate_is_image']) && is_array($child['#upload_validators']['file_validate_is_image']) && empty($child['#upload_validators']['file_validate_is_image'])) {
        unset($element[$delta]['#upload_validators']['file_validate_is_image']);
      } 
    }
  }
}

I've just come across this issue and the fix in #8 has sorted my problem.

I've not checked to see if there are any security issues with removing that line however the system I needed it for is internal anyway and only used by a couple of known users so it's not a problem in my case.