DSpace 7: submission forms issue with check for mandatory fields

[f-rapp]

Describe the bug
Submission forms: A qualdrop-value field which is marked as mandatory is not accepted by DSpace as "present", although a value was entered.

In the example:
The fields dc.contributor.author, field dc.contributor.illustrator are combined into a qualdrop_value field.

The illustrator is given, but the qualdrop_value field is not accepted as "present"
Enter dc.contributor.author instead, and the qualdrop_value field is accepted as "present".

The problem seems to be another mandatory dc.contributor.author field which is present in the same submission forms. However, this other field has other type-bind value and thus should not be considered by DSpace when checking for mandatory fields.

Version 7.6.1, Mozilla Firefox

To Reproduce
Steps to reproduce the behavior:

1. Add the following section to your submission-forms.xml:

<row>		   	   
	<field>
		<dc-schema>dc</dc-schema>
		<dc-element>contributor</dc-element>
		<dc-qualifier></dc-qualifier>
		<repeatable>true</repeatable>
		<label>Autor / Illustrator</label>
		<input-type value-pairs-name="ContributorTypes">qualdrop_value</input-type>
		<hint></hint>
		<required>mandatory</required>
		<type-bind>Book</type-bind>
		 </field>
</row>
<row>
		 <field>
		<dc-schema>dc</dc-schema>
		<dc-element>contributor</dc-element>
		<dc-qualifier></dc-qualifier>
		<repeatable>true</repeatable>
		<label>Author</label>
		<input-type>onebox</input-type>
		<hint></hint>
		<required>mandatory</required>
		<type-bind>Article</type-bind>
		 </field>
</row>

as well as the value-pairs

  <value-pairs value-pairs-name="ContributorTypes" dc-term="">
    <pair>
      <displayed-value>Author</displayed-value>
      <stored-value>author</stored-value>
    </pair>
    <pair>
      <displayed-value>Illustrator</displayed-value>
      <stored-value>illustrator</stored-value>
    </pair>
  </value-pairs>

2. Choose the modified submission forms and select Type (dc.type) = Book.
3. Enter an illustrator, auto-save and check whether DSpace accepts the field as "present".
4. Then enter an author instead, auto-save and check whether DSpace accepts the field as "present".

Expected behavior
The mandatory qualdrop_value field is accepted as "present" as soon as one value is entered.

Related work

[tdonohue]

Several bugs appear to exist related to qualdrop fields. Linking these all together as related as they might be claimed/fixed together.

• DSpace 7: previously entered qualdrop value field is deleted when adding a new (emtpy) line with the same(!) qualifier and then deleting it #2567
• DSpace 7: Not possible to reorder values of qualdrop_value fields during submission #1431

Also another ticket related to the mandatory field check: #2572

Moving this to the 7.6.x maintenance board in search of volunteer