Ford crashes if a generic binding references a procedure binding that lacks a double colon

[rouson]

As the transcript below demonstrates ford version 6.2.4 crashes when a type-bound procedure binding doesn't include a double colon (::) and the procedure is a specific binding referenced by a generic binding on the same type. The crash disappears if either a double-colon is added to the procedure binding (procedure :: total) or if the generic binding is removed.

% tree 
.
├── ford.md
└── src
    └── subdomain_m.f90

1 directory, 2 files

% cat ford.md 
---
project: Reproducer

% cat src/subdomain_m.f90 
module subdomain_m
  type subdomain_t 
  contains
    procedure total
    generic :: operator(+) => total
  end type
  interface
    module function total(lhs, rhs)
      class(subdomain_t), intent(in) :: lhs, rhs
      type(subdomain_t) total
    end function
  end interface
end module

% ford --version
ford version 6.2.4

% ford ford.md 
Reading file src/subdomain_m.f90

Processing documentation comments...
Correlating information from different parts of your project...

Creating HTML documentation...
Creating search index:   0%|                                                                                  | 0/4 [00:00<?, ?/s]Error rendering page '/Users/rouson/Repositories/ford-reproducer/doc/type/subdomain_t.html'
Creating search index:   0%|                                                                                  | 0/4 [00:00<?, ?/s]
Traceback (most recent call last):
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/ford/output.py", line 290, in html
    return self.render(self.data, self.proj, self.obj)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/ford/output.py", line 424, in render
    return template.render(data, project=project, **{self.payload_key: object})
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/jinja2/environment.py", line 1301, in render
    self.environment.handle_exception()
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/jinja2/environment.py", line 936, in handle_exception
    raise rewrite_traceback_stack(source=source)
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/ford/templates/type_page.html", line 1, in top-level template code
    {% extends "base.html" %}
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/ford/templates/base.html", line 151, in top-level template code
    {% block body %}
^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/ford/templates/type_page.html", line 92, in block 'body'
    {{ macros.bound_info(bp) }}
^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/jinja2/runtime.py", line 777, in _invoke
    rv = self._func(*arguments)
         ^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/ford/templates/macros.html", line 351, in template
    {{ binding_summary(bind) }}
^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/jinja2/runtime.py", line 777, in _invoke
    rv = self._func(*arguments)
         ^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/ford/templates/macros.html", line 284, in template
    {{ proc_line(proc, proto=proto) }}
^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/jinja2/runtime.py", line 777, in _invoke
    rv = self._func(*arguments)
         ^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/ford/templates/macros.html", line 428, in template
    {{ deprecated(proc) }}
  ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/jinja2/runtime.py", line 777, in _invoke
    rv = self._func(*arguments)
         ^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/ford/templates/macros.html", line 156, in template
    {%- if entity.meta['deprecated'] -%}
  ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/jinja2/environment.py", line 466, in getitem
    return obj[argument]
           ~~~^^^^^^^^^^
jinja2.exceptions.UndefinedError: 'str object' has no attribute 'meta'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/homebrew/bin/ford", line 8, in <module>
    sys.exit(run())
             ^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/ford/__init__.py", line 648, in run
    main(proj_data, proj_docs, md)
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/ford/__init__.py", line 632, in main
    docs = ford.output.Documentation(proj_data, proj_docs_, project, page_tree)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/ford/output.py", line 189, in __init__
    self.tipue.create_node(p.html, p.loc, p.meta)
                           ^^^^^^
  File "/opt/homebrew/Cellar/ford/HEAD-69c2084/libexec/lib/python3.11/site-packages/ford/output.py", line 292, in html
    raise RuntimeError(
RuntimeError: Error rendering 'subdomain_t.html' for 'subdomain_t' : 'str object' has no attribute 'meta'

[ZedThree]

Oof, not good! Thanks for the very clear reproducer @rouson, I will try and get this fixed as soon as I can.