### Steps to reproduce

1. Add a custom field of type `Text` to a work package variant.

2. Enter a text longer than Begin of the insertion255End of the insertion Begin of the deletion 256End of the deletion characters.

3. Save the work package.

4. Observe that the text spans multiple lines in the work package detail view.

5. Click the field to edit it. The input is displayed as a single-line field.

6. Open the work package table. The text is displayed in truncated form.


### What is the buggy behavior?

* Text custom fields allow users to enter an unlimited number of characters, although they are intended for single-line input. Begin of the deletion

* Long text values span multiple lines in the work package detail view.

* The display and editing behavior is inconsistent.End of the deletion


### What is the expected behavior?

* Text custom fields have a maximum length of Begin of the insertion255End of the insertion Begin of the deletion 256End of the deletion characters.

* Users cannot save text custom field values exceeding Begin of the insertion255End of the insertion Begin of the deletion 256End of the deletion characters.

* Begin of the insertionMigration strategy:

* End of the insertion Existing values exceeding Begin of the insertion255End of the insertion Begin of the deletion 256End of the deletion characters remain unchanged and can still be displayed. Begin of the insertion

End of the insertion Begin of the deletion

End of the deletion * Invalid text custom field values do not prevent changes to other attributes from being saved. Begin of the insertionSo it is possible to change the subject even though the text in the field is longer than 255 chars.

End of the insertion Begin of the deletion

End of the deletion * Admins can Begin of the insertionmanuallyEnd of the insertion convert text custom fields to long text fields. Begin of the insertion

End of the insertion Begin of the deletion

End of the deletion * Begin of the insertionAdmins can not convert a long text field to a text field.

* End of the insertion Converting a text custom field to a long text field is irreversible Begin of the insertion


End of the insertion Begin of the deletion


End of the deletion ### Begin of the deletion Screenshots

#### input form:

<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/926771/content"></div><figcaption class="op-uc-figure--description">The default length is 0, which means unlimited</figcaption></figure>

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#### Work package detail view:

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<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/926775/content">

#### Work package detail view in input mode

<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/926778/content"></div><figcaption class="op-uc-figure--description">When clicked, the representation switches back to single line input</figcaption></figure>

#### Work package list

<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/926780/content"></div><figcaption class="op-uc-figure--description">The work package list shows the long plain text truncated</figcaption></figure>

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### Environment information

This is happening in all environments.

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