Todos in list of todos may contain wrong links to documents

[dbitouze]

Describe the bug
Suppose the following minimal structure:

source
├── conf.py
├── folder1
│   └── file1.rst
├── folder2
│   └── file2.rst
├── index.rst
├── _static
└── _templates

where:

• source/conf.py contains:

extensions = [
    'sphinx.ext.todo',
]
todo_include_todos = True
todo_link_only = True

• source/index.rst contains:

.. Test documentation master file, created by
   sphinx-quickstart on Fri Jan 29 15:53:41 2021.
   You can adapt this file completely to your liking, but it should at least
   contain the root `toctree` directive.

Welcome to Test's documentation!
================================

.. toctree::
   :maxdepth: 2
   :caption: Contents:
   :glob:
   :hidden:

   */*

Todos
=====
.. todolist::

Indices and tables
==================

* :ref:`genindex`
* :ref:`modindex`
* :ref:`search`

• source/folder1/file1.rst contains:

Title 1
=======

.. todo:: See :doc:`Title 2 </folder2/file2>`

• source/folder2/file2.rst contains:

Title 2
=======

After a make html:

• the todo in build/html/folder1/file1.html contains the (right) link .../build/html/folder2/file2.html,
• the todo in build/html/index.html contains the (wrong) link ..../build/folder2/file2.html.

To Reproduce
See the joined minimal project.

Expected behavior
Todos in list of todos should contain right links to documents.

Your project
test-3.4.3.tar.gz

Environment info

• OS: Linux Mageia 7
• Python version: 3.7.9
• Sphinx version: 3.4.3
• Sphinx extensions: sphinx.ext.todo