"assert parentSymbol" in cpp domain when input is misaligned

[randombit]

The following input causes an assertion failure:

My Thing
===========

.. cpp:class:: Class

      .. cpp:function:: Class(int f)

         Does something with ints

     .. cpp:function:: Class(double f)

         Does something with doubles

      .. cpp:function:: Class(string f)

         Does something with strings

Note that the second declaration is not indented correctly (one space is missing).

This causes the following error:

Target:  string.. [100%] floof                                                                                                                                                                 
ParentKey:  [(<ASTNestedNameElement Class>, None), (<ASTNestedNameElement Class>, None), (<ASTNestedNameElement Class>, None)]

Exception occurred:
  File "/usr/lib/python3.6/site-packages/sphinx/domains/cpp.py", line 6133, in _resolve_xref_inner
    assert parentSymbol  # should be there
AssertionError
The full traceback has been saved in /home/jack/var/tmp/sphinx-err-851mc0mm.log, if you want to report the issue to the developers.

Traceback log is

# Sphinx version: 1.7.5
# Python version: 3.6.6 (CPython)
# Docutils version: 0.14 
# Jinja2 version: 2.10
# Last messages:
#   done
#   
#   preparing documents...
#   
#   done
#   
#   writing output... [ 50%] contents
#   
#   writing output... [100%] floof
#   
# Loaded extensions:
#   alabaster (0.7.11) from /usr/lib/python3.6/site-packages/alabaster/__init__.py
Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/sphinx/cmdline.py", line 304, in main
    app.build(args.force_all, filenames)
  File "/usr/lib/python3.6/site-packages/sphinx/application.py", line 331, in build
    self.builder.build_update()
  File "/usr/lib/python3.6/site-packages/sphinx/builders/__init__.py", line 342, in build_update
    'out of date' % len(to_build))
  File "/usr/lib/python3.6/site-packages/sphinx/builders/__init__.py", line 403, in build
    self.write(docnames, list(updated_docnames), method)
  File "/usr/lib/python3.6/site-packages/sphinx/builders/__init__.py", line 440, in write
    self._write_serial(sorted(docnames))
  File "/usr/lib/python3.6/site-packages/sphinx/builders/__init__.py", line 447, in _write_serial
    doctree = self.env.get_and_resolve_doctree(docname, self)
  File "/usr/lib/python3.6/site-packages/sphinx/environment/__init__.py", line 813, in get_and_resolve_doctree
    self.apply_post_transforms(doctree, docname)
  File "/usr/lib/python3.6/site-packages/sphinx/environment/__init__.py", line 860, in apply_post_transforms
    transformer.apply_transforms()
  File "/usr/lib/python3.6/site-packages/sphinx/transforms/__init__.py", line 96, in apply_transforms
    Transformer.apply_transforms(self)
  File "/usr/lib/python3.6/site-packages/docutils/transforms/__init__.py", line 171, in apply_transforms
    transform.apply(**kwargs)
  File "/usr/lib/python3.6/site-packages/sphinx/transforms/post_transforms/__init__.py", line 90, in apply
    typ, target, node, contnode)
  File "/usr/lib/python3.6/site-packages/sphinx/domains/cpp.py", line 6205, in resolve_xref
    target, node, contnode)[0]
  File "/usr/lib/python3.6/site-packages/sphinx/domains/cpp.py", line 6133, in _resolve_xref_inner
    assert parentSymbol  # should be there
AssertionError

Of course indenting correctly fixes the issue, but this took some time to figure out.

There are a couple of other issues about this assertion (#2413, #2536) but they seem to be caused by an unrelated (and already fixed) issue with handling duplicate declarations.

• OS: Arch Linux
• Python version: 3.6.6
• Sphinx version: 1.7.5

[jakobandersen]

Thanks for reporting! It should be fixed in the upcoming version 1.8. A warning will be issue for the last declaration (Class(string f)), that it is a nested declaration of another function, and the declaration (along with any content) will be completely ignored.