Viewer does not support local files on Chromium

[schlamar]

Configuration:

• Web browser and its version: QtWebEngine 5.12 (Chromium 69), Chrome 72
• Operating system and its version: Windows 7
• PDF.js version: 2.0.943, 2.1.266
• Is a browser extension: No

Steps to reproduce the problem:

1. Open viewer locally (file:///C:/pdftest/web/viewer.html)

What is the expected behavior?

Embedded PDF shown (it works in Firefox ESR 60).

What went wrong?

Error in console: Fetch API cannot load file:///C:/pdftest/web/compressed.tracemonkey-pldi-09.pdf. URL scheme must be "http" or "https" for CORS request.

I have seen #9361 and #9020 but I don't think that's the solution in this case.

[Snuffleupagus]

As is clearly mentioned in the README, see https://github.com/mozilla/pdf.js#getting-the-code, not all browsers support the file:// protocol:

Finally, you need to start a local web server as some browsers do not allow opening PDF files using a file:// URL.

[schlamar]

Chrome supports the file protocol, as it works with the built-in PDF viewer and with the chrome extension (which was apparently fixed in #9363). So I'm pretty sure this is a bug in pdf.js and not a missing feature in Chrome.

fetch with file:// doesn't work in Firefox either (just try fetch("file:///C:/pdftest/web/compressed.tracemonkey-pldi-09.pdf" in console). So there must be a slightly difference opening the viewer in Firefox and on Chrome.

[schlamar]

OK, I found it:

{
  var isNodeJS = __w_pdfjs_require__(4);

  if (isNodeJS()) {
    var PDFNodeStream = __w_pdfjs_require__(165).PDFNodeStream;

    pdfjsDisplayAPI.setPDFNetworkStreamFactory(function (params) {
      return new PDFNodeStream(params);
    });
  } else if (typeof Response !== 'undefined' && 'body' in Response.prototype && typeof ReadableStream !== 'undefined') {
    var PDFFetchStream = __w_pdfjs_require__(168).PDFFetchStream;

    pdfjsDisplayAPI.setPDFNetworkStreamFactory(function (params) {
      return new PDFFetchStream(params);
    });
  } else {
    var PDFNetworkStream = __w_pdfjs_require__(169).PDFNetworkStream;

    pdfjsDisplayAPI.setPDFNetworkStreamFactory(function (params) {
      return new PDFNetworkStream(params);
    });
  }
}

My Firefox (60 ESR) doesn't have body in Response.prototype, so it is using the PDFNetworkStream (which works with file URLs).

Looks like the logic not to use fetch for file protocol (#9363) is totally missing in your release builds.

I assume the viewer is broken on a newer Firefox, too.

Edit Removing the else if branch in pdf.js from the code above makes it work.

Edit2 Firefox 65 works, as it supports fetch with file protocol. My point from above is still valid. The fix from #9363 is not in the release build.