Attach (recommended) or Link to PDF file here:
[example.pdf](https://github.com/mozilla/pdf.js/files/6916129/example.pdf)

Configuration:
- Web browser and its version: Chrome, Firefox
- Operating system and its version: all
- PDF.js version: various versions, including 2.11.54
- Is a browser extension: no

Screenshot with visible textLayer:
![Screenshot from 2021-08-02 13-05-03](https://user-images.githubusercontent.com/6362989/127844878-f85e291f-2060-4028-be09-7835f32ccfaa.png)

Which means some letters at the beginning/end of text selection are missing when copying text.

)
              );
              return;
            }
            arg = c.getRgb(arg, 0);
            fn = OPS.etFllRGBClr;
            break;
          cae OPS.etStrkeClrN:
            c = tateManager.tate.trkeClrSpace;
            f (c.name === "Pattern") {
              next(
                elf.handleClrN(
                  peratrLt,
                  OPS.etStrkeClrN,
                  arg,
                  c,
                  pattern,
                  reurce,
                  tak,
                  lcalClrSpaceCache,
                  lcalTlngPatternCache,
                  lcalShadngPatternCache
                )
              );
              return;
            }
            arg = c.getRgb(arg, 0);
            fn = OPS.etStrkeRGBClr;
            break;
          cae OPS.hadngFll: