From d7fb654524149faaa278b340bde6d1fc46f9d15d Mon Sep 17 00:00:00 2001
From: milde <milde@929543f6-e4f2-0310-98a6-ba3bd3dd1d04>
Date: Sat, 4 May 2024 08:58:36 +0000
Subject: [PATCH] New SubStructural element category class.

Fix categories: (cf. docs/ref/doctree.txt)

`<docinfo>` is SubStructural, not Bibliographic.
`<transition>` is SubStructural, not Structural.

git-svn-id: http://svn.code.sf.net/p/docutils/code/trunk@9683 929543f6-e4f2-0310-98a6-ba3bd3dd1d04
---
 docutils/HISTORY.txt       | 17 +++++++++++++++--
 docutils/docutils/nodes.py | 20 ++++++++++++++------
 2 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/docutils/HISTORY.txt b/docutils/HISTORY.txt
index fb2d28c10..a917e95c1 100644
--- a/docutils/HISTORY.txt
+++ b/docutils/HISTORY.txt
@@ -17,8 +17,21 @@
 Release 0.22b.dev (unpublished)
 ===============================
 
-* Add tox.ini to pyproject.toml to be in sdist (bug #486).
-* Fix license issue (bug #487).
+* General
+
+  - Add tox.ini to pyproject.toml to be in sdist (bug #486).
+  - Fix license issue (bug #487).
+
+* docutils/nodes.py
+
+  - New `SubStructural` element category class.
+  - Fix element categories.
+
+* docutils/transforms/frontmatter.py
+
+  - Adapt `DocInfo` to fixed element categories.
+
+
 
 Release 0.21.2 (2024-04-23)
 ===========================
diff --git a/docutils/docutils/nodes.py b/docutils/docutils/nodes.py
index ef5f3527d..fad6903e0 100644
--- a/docutils/docutils/nodes.py
+++ b/docutils/docutils/nodes.py
@@ -1127,6 +1127,14 @@ class Structural:
     """
 
 
+class SubStructural:
+    """`Structural Subelements`__ are valid children of Structural Elements.
+
+    __ https://docutils.sourceforge.io/docs/ref/doctree.html
+       #structural-subelements
+    """
+
+
 class Body:
     """`Body elements`__.
 
@@ -1583,8 +1591,8 @@ class document(Root, Structural, Element):
 #  Title Elements
 # ================
 
-class title(Titular, PreBibliographic, TextElement): pass
-class subtitle(Titular, PreBibliographic, TextElement): pass
+class title(Titular, PreBibliographic, SubStructural, TextElement): pass
+class subtitle(Titular, PreBibliographic, SubStructural, TextElement): pass
 class rubric(Titular, General, TextElement): pass
 
 
@@ -1592,7 +1600,7 @@ class rubric(Titular, General, TextElement): pass
 #  Meta-Data Element
 # ==================
 
-class meta(PreBibliographic, Element):
+class meta(PreBibliographic, SubStructural, Element):
     """Container for "invisible" bibliographic data, or meta-data."""
 
 
@@ -1600,7 +1608,7 @@ class meta(PreBibliographic, Element):
 #  Bibliographic Elements
 # ========================
 
-class docinfo(Bibliographic, Element): pass
+class docinfo(SubStructural, Element): pass
 class author(Bibliographic, TextElement): pass
 class organization(Bibliographic, TextElement): pass
 class address(Bibliographic, FixedTextElement): pass
@@ -1620,7 +1628,7 @@ class authors(Bibliographic, Element):
 #  Decorative Elements
 # =====================
 
-class decoration(PreBibliographic, Element):
+class decoration(PreBibliographic, SubStructural, Element):
     """Container for header and footer."""
 
     def get_header(self):
@@ -1676,7 +1684,7 @@ class sidebar(Structural, Element):
     """
 
 
-class transition(Structural, Element):
+class transition(SubStructural, Element):
     """Transitions are breaks between untitled text parts.
 
     A transition may not begin or end a section or document, nor may two
-- 
2.11.4.GIT