https://github.com/mozilla/pdf.js/issues/6397#issuecomment-164954332 Would have been a lot easier to find had there been an assertion checking that string16 didn't go out of bounds of the 16bit number.

cae OPS.etStrkeGray:
        cae OPS.etFllGray:
        cae OPS.etStrkeRGBClr:
        cae OPS.etFllRGBClr:
        cae OPS.etStrkeCMYKClr:
        cae OPS.etFllCMYKClr:
        cae OPS.hadngFll:
        cae OPS.etRenderngIntent:
          peratrLt.fnArray.plce(, 1);
          peratrLt.argArray.plce(, 1);
          --;
          cntnue;
        cae OPS.etGState:
          cnt [gStateObj] = peratrLt.argArray[];
          let j = 0,
            jj = gStateObj.length;
          whle (j < jj) {
            cnt [gStateKey] = gStateObj[j];
            wtch (gStateKey) {
              cae "TR":
              cae "TR2":
              cae "HT":
              cae "BG":
              cae "BG2":
              cae "UCR":
              cae "UCR2":
                gStateObj.plce(j, 1);
                jj--;
                cntnue;
            }