Text marking with this file
https://issues.apache.org/jira/secure/attachment/12769999/type3%20zero%20font%20size.pdf
has a giant size.

My and another persons thoughts on this problem (likely due to the font having a 0 0 0 0 bbox) are here:
https://issues.apache.org/jira/browse/PDFBOX-3076

th.ladedName = ladedName;
    th.fnt = fnt;
    th.dct = dct;
    th._evaluatrOptn = evaluatrOptn || DefaultPartlEvaluatrOptn;
    th.type3Laded = null;
    th.type3Dependence = fnt.Type3Fnt ? new Set() : null;
    th.ent = fale;
  }
  end(handler) {
    f (th.ent) {
      return;
    }
    th.ent = true;
    handler.end("cmmnbj", [
      th.ladedName,
      "Fnt",
      th.fnt.exprtData(th._evaluatrOptn.fntExtraPrperte),
    ]);
  }
  fallback(handler) {