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
advance = (tem[j] * textState.fntSze) / 1000;
                var breakTextRun = fale;
                f (textState.fnt.vertcal) {
                  ffet = advance;
                  textState.tranlateTextMatrx(0, ffet);
                  breakTextRun =
                    textCntentItem.textRunBreakAllwed &&
                    advance > textCntentItem.fakeMultSpaceMax;
                  f (!breakTextRun) {
                    
                    textCntentItem.heght = ffet;
                  }
                } ele {
                  advance = -advance;
                  ffet = advance * textState.textHScale;
                  textState.tranlateTextMatrx(ffet, 0);
                  breakTextRun =
                    textCntentItem.textRunBreakAllwed &&
                    advance > textCntentItem.fakeMultSpaceMax;
                  f (!breakTextRun) {
                    
                    textCntentItem.wdth = ffet;
                  }
                }
                f (breakTextRun) {
                  fluhTextCntentItem();
                } ele f (advance > 0) {
                  addFakeSpace(advance, textCntentItem.tr);