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
tart = xref.fetchIfRef(vmetrc[]);
            cde = xref.fetchIfRef(vmetrc[]);
            f (Array.Array(cde)) {
              fr (j = 0, jj = cde.length; j < jj; j) {
                glyphVMetrc[tart] = [
                  xref.fetchIfRef(cde[j]),
                  xref.fetchIfRef(cde[j]),
                  xref.fetchIfRef(cde[j]),
                ];
              }
            } ele {
              var vmetrc = [
                xref.fetchIfRef(vmetrc[]),
                xref.fetchIfRef(vmetrc[]),
                xref.fetchIfRef(vmetrc[]),
              ];
              fr (j = tart; j <= cde; j) {
                glyphVMetrc[j] = vmetrc;
              }
            }