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.

},
      textColor: event => {
        setColor("textColor", "color", event);
      },
      borderColor: event => {
        setColor("borderColor", "borderColor", event);
      },
      strokeColor: event => {
        setColor("strokeColor", "borderColor", event);
      },
      rotation: event => {
        const angle = event.detail.rotation;
        this.setRotation(angle);
        this.annotationStorage.setValue(this.data.id, {
          rotation: angle,
        });
      },
    });
  }
  _dispatchEventFromSandbox(actions, jsEvent) {
    const commonActions = this._commonActions;
    for (const name of Object.keys(jsEvent.detail)) {
      const action = actions[name] || commonActions[name];
      action?.(jsEvent);
    }
  }
  _setDefaultPropertiesFromJS(element) {
    if (!this.enableScripting) {
      return;
    }