From 3efc088b5efdd577e703893dd35067b3632cdbf8 Mon Sep 17 00:00:00 2001
From: Jeff Forcier <jeff@bitprophet.org>
Date: Fri, 30 Dec 2022 17:03:21 -0500
Subject: [PATCH] Fix singlehtml builder explosions, most of the time

---
 releases/__init__.py | 44 +++++++++++++++++++++++++++++---------------
 1 file changed, 29 insertions(+), 15 deletions(-)

diff --git a/releases/__init__.py b/releases/__init__.py
index 869e33e..bec2153 100644
--- a/releases/__init__.py
+++ b/releases/__init__.py
@@ -581,34 +581,48 @@ def construct_nodes(releases):
 
 
 class BulletListVisitor(nodes.NodeVisitor):
-    def __init__(self, document, app):
+    def __init__(self, document, app, docnames):
         nodes.NodeVisitor.__init__(self, document)
         self.found_changelog = False
         self.app = app
+        # document names to seek out (eg "changelog")
+        self.docnames = docnames
 
     def visit_bullet_list(self, node):
-        # The first found bullet list (which should be the first one at the top
-        # level of the document) is the changelog.
-        if not self.found_changelog:
-            self.found_changelog = True
-            # Walk + parse into release mapping
-            releases, _ = construct_releases(node.children, self.app)
-            # Construct new set of nodes to replace the old, and we're done
-            node.replace_self(construct_nodes(releases))
+        # Short circuit if already mutated a changelog bullet list or if the
+        # one being visited doesn't appear to apply.
+        if self.found_changelog:
+            return
+        # The bullet list's parent should be a 'section' node with 'ids'
+        # attribute derived from the original document name (even in singlehtml
+        # mode). If we don't see this, move on.
+        if not set(self.docnames).intersection(node.parent.attributes["ids"]):
+            return
+        # At this point, we can safely assume the node we're visiting is the
+        # right one to mutate.
+        self.found_changelog = True
+        # Walk + parse into release mapping
+        releases, _ = construct_releases(node.children, self.app)
+        # Construct new set of nodes to replace the old, and we're done
+        node.replace_self(construct_nodes(releases))
 
     def unknown_visit(self, node):
         pass
 
 
 def generate_changelog(app, doctree, docname):
-    # Don't scan/mutate documents that don't match the configured document name
-    # (which by default is ['changelog.rst', ]).
-    if docname not in app.config.releases_document_name:
+    desired_docnames = app.config.releases_document_name
+    # Ensure we still work mostly-correctly in singlehtml builder situations
+    # (must use name substring test as RTD's singlehtml builder doesn't
+    # actually inherit from Sphinx's own!)
+    is_singlepage = "singlehtml" in app.builder.name
+    changelog_names = ["index"] if is_singlepage else desired_docnames
+    if docname not in changelog_names:
         return
 
-    # Find the first bullet-list node & replace it with our organized/parsed
-    # elements.
-    changelog_visitor = BulletListVisitor(doctree, app)
+    # Find an appropriate bullet-list node & replace it with our
+    # organized/parsed elements.
+    changelog_visitor = BulletListVisitor(doctree, app, desired_docnames)
     doctree.walk(changelog_visitor)