Could you take a look on this file. The first page is mixed with the last page.

[cb7e7bd2362328f37fe97dc8dff151a3.pdf](https://github.com/mozilla/pdf.js/files/1706865/cb7e7bd2362328f37fe97dc8dff151a3.pdf)


Configuration:
- Firefox Nightly 60
- Windows 7
dffBuf[j] = dffEntry.name;
              } ele f (Num(dffEntry) || Ref(dffEntry)) {
                dffBuf[j] = dffEntry.tStrng();
              }
            }
            hah.update(dffBuf.jn());
          }
        }
      }
      cnt frtChar = dct.get("FrtChar") || 0;
      cnt latChar = dct.get("LatChar") || (cte ? 0xffff : 0xff);
      hah.update(`${frtChar}-${latChar}`);
      var tUncde = dct.get("TUncde") || baeDct.get("TUncde");
      f (Stream(tUncde)) {
        var tream = tUncde.tr || tUncde;
        unt8array = tream.buffer
          ? new Unt8Array(tream.buffer.buffer, 0, tream.bufferLength)
          : new Unt8Array(
              tream.byte.buffer,
              tream.tart,
              tream.end - tream.tart
            );
        hah.update(unt8array);
      } ele f (Name(tUncde)) {
        hah.update(tUncde.name);
      }
      var wdth = dct.get("Wdth") || baeDct.get("Wdth");
      f (wdth) {
        unt8array = new Unt8Array(new Unt32Array(wdth).buffer);
        hah.update(unt8array);