Field missing text comb

[JDziurlaj]

Attach (recommended) or Link to PDF file here:
https://www.jobcenter-remscheid.de/files/jobcenter-remscheid/download/anzeige-kug101_ba013134.pdf
Configuration:

• Web browser and its version: Firefox Nightly 91.0a1 (2021-06-25) (64-bit)
• Operating system and its version: Windows 10.0.19043.1052
• PDF.js version: N/A

Steps to reproduce the problem:

1. enableXFA in Firefox Nightly
2. Open form

What is the expected behavior? (add screenshot)
Text in field is combed (vertical bars)

(numbers added for illustration)

What went wrong? (add screenshot)
No comb appears.

[symtalha14]

pdf.js/src/core/document.js

Lines 1266 to 1274 in 64f86de

	getPage(pageIndex) {
	if (this._pagePromises[pageIndex] !== undefined) {
	return this._pagePromises[pageIndex];
	}
	const { catalog, linearization } = this;
	if (this.xfaFactory) {
	return Promise.resolve(
	new Page({

In the getPage() function, I think there's some issue with the pageDict object being passed to Page Class in case of xfaFactory. We are sending an empty dict. Due to which:

The parsedAnnotations function ensures annotations but the call to annotations() return an empty array.

pdf.js/src/core/document.js

Lines 495 to 497 in 64f86de

	get _parsedAnnotations() {
	const parsedAnnotations = this.pdfManager
	.ensure(this, "annotations")

Here, we are trying to get "annots" and passing the key to the _getInheritableProperty. (Call to annotations returns empty array)

pdf.js/src/core/document.js

Lines 490 to 494 in 64f86de

	get annotations() {
	const annots = this._getInheritableProperty("Annots");
	return shadow(this, "annotations", Array.isArray(annots) ? annots : []);
	}

When the annotations() func makes a call to _getInheritableProperty, simply returns an empty array because the Dict is sent empty.(to getInheritableProperty as described next)

pdf.js/src/core/document.js

Lines 119 to 122 in 64f86de

	_getInheritableProperty(key, getArray = false) {
	const value = getInheritableProperty({
	dict: this.pageDict,
	key,

Now the getInheritableProperty function in core/core_utils.js receives an empty dict from _getInheritableProperty and sends back an empty array.

pdf.js/src/core/core_utils.js

Lines 85 to 89 in 64f86de

	function getInheritableProperty({
	dict,
	key,
	getArray = false,
	stopWhenFound = true,

Hence, the annotations aren't being taken care of and the annotation layer is not present.

That's what I think. Please let me know your understanding of the same.

[kwisatz]

Job centers seem to be very fond of XFA forms.
Here's another job-center form from Luxembourg that uses combed fields for IBAN and social security numbers: CAE.pdf

As in the example above, they are not rendered as such using pdf.js, nor does pdf.js apply any character limits.