Missing or legacy number validation

Updating introduction.

Make a table.

First failing tests for user_picture_file_size, filter_url_length and minimum_word_size.

image_jpeg_quality is properly validated.

New tests created.

That + attempts to add validation.

Convert the other occurences.

I am not sure why #3 is still failing, that is: The user configuration form doesn't save invalid input, but it says it does and it also doesn't show validation errors.

Ok, typo there.

This should do it.

Just leave it blank ;)

Seriously: The number will only be validated if it is not ''. So either valid or blank are allowed, unless #required is set.

/**
 * Form element validation handler for #type 'number'.
 *
 * Note that #required is validated by _form_validate() already.
 */
function form_validate_number(&$element, &$form_state) {
  $value = $element['#value'];
  if ($value === '') {
    return;
  }
  // ...

If everything that's there is OK, that's it.

Rerolling because of #1299424: Allow one module per directory and move system tests to core/modules/system.

Thank you for the testing, bleen18.

Not to forget: The ones with the ! need to be backported to D7, though we cant use the shiny number element there.

Fortunately only the simple cases were missing validation. That is only integers that must be positive.

Next try.

Edit: OK. I believe this is ready.