Generated PDF's outline/bookmarks don't link to the correct page

[icnocop]

Operation System: Windows 10 64-bit

DocFX Version Used: 2.41

Template used: default

Steps to Reproduce:

1. Download and extract docfx-pdf-outline-bug.zip to a directory of your choice.

2. Run build.cmd
   Note: docfx.exe and wkhtmltopdf.exe should be in your %PATH%.
   Otherwise, update build.cmd as follows:

set PATH=<path to wkhtmltox>;%PATH%
"<path to docfx>\docfx.exe" docfx.json

I tested with both wkhtmltox v0.12.4_msvc2015-win64 and v0.12.5-1.msvc2015-win64.

3. Open the generated PDF file in _pdf\*.pdf in Adobe Acrobat Reader DC 2019.010.20098.
4. Show the Bookmarks pane.
5. Click on the Page 2 bookmark for example.

Expected Behavior:

I expected the Page 2 bookmark to take me to page 5 in the PDF.

Actual Behavior:

The Page 2 bookmark takes me to page 7 in the PDF.

[icnocop]

This was caused by trying to use wkhtmltopdf's cover and toc with docfx's default outline which aren't compatible.

The fix was part of PR #4289 and commit 79b78aa.

So basically, you can use wkhtmltopdf's outline by setting the new outline JSON property to WkDefaultOutline.