Attach (recommended) or Link to PDF file here:
PDF is [Sample lease contract 26.pdf](https://github.com/mozilla/pdf.js/files/1500985/Sample.lease.contract.26.pdf)

Steps to reproduce the problem:
I am using [https://mozilla.github.io/pdf.js/web/viewer.html](url) to preview pdf by opening the pdf.

now am searching for "**made is**" but its not showing in the pdfjs

and while selecting and copying pdf  text it has no space in b/w words

);
      const pdfDoc = await loadingTask.promise;
      const pdfPage = await pdfDoc.getPage(1);
      const { items } = await pdfPage.getTextContent();
      const text = mergeText(items);
      expect(text).toEqual(
        "침하게 흐린 품이 눈이 올 듯하더니 눈은 아니 오고 얼다가 만 비가 추"
      );
      await loadingTask.destroy();
    });
    it("gets empty structure tree", async function () {
      const tree = await page.getStructTree();
      expect(tree).toEqual(null);
    });
    it("gets simple structure tree", async function () {
      const loadingTask = getDocument(
        buildGetDocumentParams("structure_simple.pdf")
      );
      const pdfDoc = await loadingTask.promise;
      const pdfPage = await pdfDoc.getPage(1);
      const tree = await pdfPage.getStructTree();
      expect(tree).toEqual({
        role: "Root",
        children: [
          {
            role: "Document",
            lang: "en-US",
            children: [
              {
                role: "H1",