Attach (recommended) or Link to PDF file [here:] Can't see how to attach a pdf here, but it is simple to create. Add a form object textbox to a pdf and make sure the option for "Multiline" is true.

Steps to reproduce the problem:
1.  Open a document with a Textbox that is set to Multiline.
2. Attempt to hit the Enter key to go to a new line.

What is the expected behavior? The cursor goes to a new line.

What went wrong? It does not go to a new line.

Link to a viewer: It can be reproduced on mozilla.github.io/pdf.js

I corrected the issue by altering the pdf.js file like this
element.addEventListener("keydown", event => { 
[...]
--} else if (event.key === "Enter") {
++ } else if (event.key === "Enter" && !this.data.multiLine) {

Our initial testing is coming through clean, and hopefully something like this code can be committed to the project in the future.

selectElement,
        [
          ["focus", "Focus"],
          ["blur", "Blur"],
          ["mousedown", "Mouse Down"],
          ["mouseenter", "Mouse Enter"],
          ["mouseleave", "Mouse Exit"],
          ["mouseup", "Mouse Up"],
          ["input", "Action"],
        ],
        event => event.target.checked
      );
    } else {
      selectElement.addEventListener("input", function (event) {
        storage.setValue(id, { value: getValue(event,  true) });
      });
    }
    if (this.data.combo) {
      this._setTextStyle(selectElement);
    } else {
      
      
    }
    this._setBackgroundColor(selectElement);
    this._setDefaultPropertiesFromJS(selectElement);
    this.container.append(selectElement);
    return this.container;
  }
}
class PopupAnnotationElement extends AnnotationElement {