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.

const { annotationCanvasMap, div, viewport } = parameters;
    this.#setDimensions(div, viewport);
    this.#setAnnotationCanvasMap(div, annotationCanvasMap);
    div.hidden = false;
  }
  /**
   * @param {HTMLDivElement} div
   * @param {PageViewport} viewport
   */
  static #setDimensions(div, { width, height, rotation }) {
    const { style } = div;
    const flipOrientation = rotation % 180 !== 0,
      widthStr = Math.floor(width) + "px",
      heightStr = Math.floor(height) + "px";
    style.width = flipOrientation ? heightStr : widthStr;
    style.height = flipOrientation ? widthStr : heightStr;
    div.setAttribute("data-main-rotation", rotation);
  }
  static #setAnnotationCanvasMap(div, annotationCanvasMap) {