chore: drop the MANIFEST.in lines that match nothing (#1794)

MANIFEST.in

@@ -1,8 +1,7 @@
 global-exclude .DS_Store
 
-global-include *.rst
 global-include *.py
-# Neither global-include reaches Markdown, which the examples' READMEs are (#719).
+# The global-include does not reach Markdown, which the examples' READMEs are (#719).
 recursive-include examples *.md
 
 prune .eggs
@@ -53,7 +52,7 @@ include README.md
 include LICENSE
 
 # Load-bearing, and missed for the same reason as ``CHANGELOG.md`` below:
-# neither ``global-include`` at the top of this file can reach a ``.cff``, so
+# the ``global-include`` at the top of this file cannot reach a ``.cff``, so
 # without this line ``CITATION.cff`` sits in the repository and in no source
 # distribution at all -- measured by building one each way, not assumed. Nor is
 # there a default to fall back on: setuptools ships ``LICENSE`` from its
@@ -71,7 +70,7 @@ include CITATION.cff
 
 # The changelog needs two lines of its own, and neither is redundant.
 #
-# ``global-include *.rst`` above matches only ``*.rst``, so the root
+# ``global-include *.py`` above matches only ``*.py``, so the root
 # ``CHANGELOG.md`` is picked up by nothing and would be absent from every source
 # distribution without this line -- measured, not assumed.
 include CHANGELOG.md
@@ -85,5 +84,9 @@ include CHANGELOG.md
 # shipped, because it is a ``toctree`` that only Sphinx can read.
 recursive-include docs/source/changelog *.rst
 
-include pcapkit/_extern
-exclude pcapkit/protocols/*/NotImplemented
+# Nothing here names ``pcapkit/_extern``. ``conda/pypcapkit/build.sh`` and
+# ``bld.bat`` create it and then run ``pip install .``, which builds the wheel
+# straight from the tree, so the conda recipe builds no sdist; its modules
+# reach that wheel through package discovery. A line naming it would warn in
+# every other build, and ``include`` of a directory matched nothing even in the
+# conda one (#1794).

docs/source/contributing/conventions/documentation.rst

@@ -298,8 +298,8 @@ Format and Mechanics
    ruled this on :issue:`719`, correcting a blanket *always* ``.rst`` that had been in
    circulation: the Sphinx documentation is reST, and the other documents --
    the READMEs included -- are Markdown where that applies. ``CONTRIBUTING.md``'s own
-   *Documentation* section records the same split. Neither ``global-include`` in
-   :file:`MANIFEST.in` reaches Markdown, so the two READMEs under :file:`examples/`
+   *Documentation* section records the same split. The ``global-include`` in
+   :file:`MANIFEST.in` does not reach Markdown, so the READMEs under :file:`examples/`
    ship through ``recursive-include examples *.md``, and any other Markdown file
    ships only if setuptools or an ``include`` line adds it.
 *  **Prose names the real defining module, not a re-export.** One strand of the

tests/project/test_build_leftovers_1773.py

@@ -6,7 +6,8 @@
   a real wheel of a stub package with :file:`setup.py`'s own ``cmdclass``.
 * Each backport's failure message names the feature that tool back-ports.
 * ``make profile`` reaches a Makefile that exists, and every ``prune`` in
-  :file:`MANIFEST.in` names a directory the repository tracks or ignores.
+  :file:`MANIFEST.in` names a directory the repository tracks or ignores. Every
+  other line there changes what the template selects (#1794).
 * No reStructuredText is tracked outside ``docs/`` (the #719 ruling), the
   examples' Markdown READMEs still ship in the sdist, and nothing points at a
   README path that no longer exists.
@@ -213,6 +214,57 @@ def test_every_prune_names_a_tracked_or_ignored_directory(self) -> None:
                 self.assertEqual(ignored.returncode, 0,
                                  f'prune {directory} names a directory git neither tracks nor ignores')
 
+    def test_every_other_directive_changes_the_selection(self) -> None:
+        """Dropping any non-``prune`` line changes which tracked files the template selects.
+
+        An exclusion may instead guard a path git ignores, as ``prune`` may above.
+        The template runs without setuptools' defaults, so ``include README.md``
+        counts as effective here although a real build ships the README anyway
+        (#1794).
+        """
+        files = tracked()
+        directives = [line.strip() for line in
+                      (ROOT / 'MANIFEST.in').read_text(encoding='utf-8').splitlines()
+                      if line.strip() and not line.lstrip().startswith('#')]
+        driver = textwrap.dedent('''
+            import json, os, sys
+            from setuptools.command.egg_info import FileList
+            data = json.loads(sys.stdin.read())
+            tracked = set(data['files'])
+
+            def select(lines):
+                listing = FileList()
+                listing.allfiles = list(data['files'])
+                for line in lines:
+                    listing.process_template_line(line)
+                return sorted({name.replace(os.sep, '/') for name in listing.files} & tracked)
+
+            lines = data['lines']
+            print(json.dumps([select(lines)] + [select(lines[:index] + lines[index + 1:])
+                                                for index in range(len(lines))]))
+        ''')
+        result = subprocess.run([sys.executable, '-c', driver], cwd=ROOT,  # nosec
+                                input=json.dumps({'files': files, 'lines': directives}),
+                                capture_output=True, text=True, check=True, timeout=120)
+        selected, *without = json.loads(result.stdout)
+        for line, rest in zip(directives, without):
+            action, *words = line.split()
+            if action == 'prune':
+                continue
+            with self.subTest(line=line):
+                if rest != selected:
+                    continue
+                if action.endswith('exclude'):
+                    if action.startswith('recursive-'):
+                        targets = [f'{words[0]}/{pattern}' for pattern in words[1:]]
+                    else:
+                        targets = words
+                    if all(subprocess.run(['git', 'check-ignore', '-q', '--no-index',  # nosec
+                                           target], cwd=ROOT, check=False).returncode == 0
+                           for target in targets):
+                        continue
+                self.fail(f'{line!r} changes nothing the template selects from the tracked files')
+
     def test_no_restructuredtext_outside_docs(self) -> None:
         stray = [name for name in tracked()
                  if name.endswith('.rst') and not name.startswith('docs/')]