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.

}
    container.style.left = `${(100 * (rect[0] - pageLLx)) / pageWidth}%`;
    container.style.top = `${(100 * (rect[1] - pageLLy)) / pageHeight}%`;
    const { rotation } = data;
    if (data.hasOwnCanvas || rotation === 0) {
      container.style.width = `${(100 * width) / pageWidth}%`;
      container.style.height = `${(100 * height) / pageHeight}%`;
    } else {
      this.setRotation(rotation, container);
    }
    return container;
  }
  setRotation(angle, container = this.container) {
    const [pageLLx, pageLLy, pageURx, pageURy] = this.viewport.viewBox;
    const pageWidth = pageURx - pageLLx;
    const pageHeight = pageURy - pageLLy;
    const { width, height } = getRectDims(this.data.rect);
    let elementWidth, elementHeight;
    if (angle % 180 === 0) {
      elementWidth = (100 * width) / pageWidth;
      elementHeight = (100 * height) / pageHeight;
    } else {
      elementWidth = (100 * height) / pageWidth;
      elementHeight = (100 * width) / pageHeight;
    }
    container.style.width = `${elementWidth}%`;
    container.style.height = `${elementHeight}%`;
    container.setAttribute("data-main-rotation", (360 - angle) % 360);
  }
  get _commonActions() {