Pages with viewbox coordinates where max<min have no text

[Deco]

Attach (recommended) or Link to PDF file here: It contains semi-private information. I can send directly to any dev willing to tackle this issue.

Configuration:

• Web browser and its version: NodeJS
• Operating system and its version: Windows 10 & Ubuntu
• PDF.js version: 3.1.81
• Is a browser extension: No

Steps to reproduce the problem:

1. Find a PDF that uses a viewport like (0, 0, 100, -200).
2. Notice that all text is treated as "outside the viewbox" (even though a coordinate like 50,-100 is completely valid in this situation)

What is the expected behavior? The text is treated as inside the page.

What went wrong? All text is treated as outside the page.

---

The problem was introduced by this new code in this commit:
18e3a98#diff-cf40014d9c7d352f3ae212e7fffe5386decf96a10e53066a4d900c3eb8fc559eR2404

The if-statement here has a naively-written condition that does not handle the case where the viewbox minimum is numerically greater than the viewbox maximum on the same axis. I believe the correct code would be:

    function compareWithLastPosition() {
      const currentTransform = getCurrentTextTransform();
      let posX = currentTransform[4];
      let posY = currentTransform[5];

      if (
        posX < Math.min(viewBox[0], viewBox[2]) ||
        posX > Math.max(viewBox[0], viewBox[2]) ||
        posY < Math.min(viewBox[1], viewBox[3]) ||
        posY > Math.max(viewBox[1], viewBox[3])
      ) {
        return false;
      }
      
      // ...

[Snuffleupagus]

Given that lack of a test-case, I'm guessing that this was fixed by PR #15773.

[Deco]

I'll check and let you know -- thanks @Snuffleupagus!