Attach (recommended) or Link to PDF file here:
[example.pdf](https://github.com/mozilla/pdf.js/files/6916129/example.pdf)

Configuration:
- Web browser and its version: Chrome, Firefox
- Operating system and its version: all
- PDF.js version: various versions, including 2.11.54
- Is a browser extension: no

Screenshot with visible textLayer:
![Screenshot from 2021-08-02 13-05-03](https://user-images.githubusercontent.com/6362989/127844878-f85e291f-2060-4028-be09-7835f32ccfaa.png)

Which means some letters at the beginning/end of text selection are missing when copying text.

properties,
          SEAC_ANALYSIS_ENABLED
        );
        cff = parser.parse();
        cff.duplicateFirstGlyph();
        const compiler = new CFFCompiler(cff);
        tables["CFF "].data = compiler.compile();
      } catch (e) {
        warn("Failed to compile font " + properties.loadedName);
      }
    }
    
    if (!tables.name) {
      tables.name = {
        tag: "name",
        data: createNameTable(this.name),
      };
    } else {
      
      const namePrototype = readNameTable(tables.name);
      tables.name.data = createNameTable(name, namePrototype);
      this.psName = namePrototype[0][6] || null;
    }
    const builder = new OpenTypeFileBuilder(header.version);
    for (const tableTag in tables) {
      builder.addTable(tableTag, tables[tableTag].data);
    }
    return builder.toArray();
  }
  convert(fontName, font, properties) {