Attach (recommended) or Link to PDF file here:  [test.pdf](https://akmer.aikucun.com/a94a8fe5ccb19ba61c4c0873d391e987982fbbd3_1616477914120_83.pdf)


Configuration:
- Web browser and its version: chrome 87.0.4280.88
- Operating system and its version: windows10
- PDF.js version: 2.6.347
- Is a browser extension:

Steps to reproduce the problem:
1. just open 

What is the expected behavior? (add screenshot)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/17724610/112087066-473f8f80-8bc8-11eb-8efb-56139ec42a9c.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

var str = this.str;
    
    var hdr = this.getBits(3);
    if (hdr & 1) {
      this.eof = true;
    }
    hdr >>= 1;
    if (hdr === 0) {
      
      var b;
      if ((b = str.getByte()) === -1) {
        throw new FormatError("Bad block header in flate stream");
      }
      var blockLen = b;
      if ((b = str.getByte()) === -1) {
        throw new FormatError("Bad block header in flate stream");
      }
      blockLen |= b << 8;
      if ((b = str.getByte()) === -1) {
        throw new FormatError("Bad block header in flate stream");
      }
      var check = b;
      if ((b = str.getByte()) === -1) {
        throw new FormatError("Bad block header in flate stream");
      }
      check |= b << 8;
      if (check !== (~blockLen & 0xffff) && (blockLen !== 0 || check !== 0)) {
        
        throw new FormatError("Bad uncompressed block length in flate stream");
      }