PDF.js stuck without feedback when Content-Range header is missing

[Rob--W]

The NetworkManager expects a Content-Range header in a specific format:

pdf.js/src/display/network.js

Lines 159 to 160 in 07765e9

	const rangeHeader = xhr.getResponseHeader("Content-Range");
	const matches = /bytes (\d+)-(\d+)\/(\d+)/.exec(rangeHeader);

If the header is missing or does not have the expected value, the regex will be null and the network manager throws at that point, and neither pendingRequest.onError nor pendingRequest.onDone is invoked.

To reproduce:

• Cherry-pick the patch with tests from Add test cases for redirected responses #19074 (if not already landed)
• In the test/webserver.mjs, comment out response.setHeader("Access-Control-Expose-Headers", "Content-Range");
• Run the test from that patch: http://[::1]:8888/test/unit/unit_test.html?spec=redirects%20block

Expected:

• Test runs to completion.

Actual:

• Test stuck and times out, console shows the following error:

Uncaught TypeError: can't access property 1, matches is null
onStateChange http://[::1]:8888/src/display/network.js:162