From de7f294f91abb2087b4479eabe6454e22e0f812f Mon Sep 17 00:00:00 2001
From: Adam Wight <adam.wight@wikimedia.de>
Date: Tue, 2 Jul 2024 10:39:35 +0200
Subject: [PATCH] Promote orphaned subrefs to the top level

This isn't the ideal solution since it doesn't exactly match the
rendered reader view, but it's a reasonable workaround and an
improvement on "undefined" numbering.

Bug: T247921
Change-Id: Ic0d88123d50e2fcb7f25e897280dbfdb6d494501
---
 modules/ve-cite/ve.dm.MWDocumentReferences.js | 39 ++++++++++++++-----
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/modules/ve-cite/ve.dm.MWDocumentReferences.js b/modules/ve-cite/ve.dm.MWDocumentReferences.js
index db62bcaa5..c8fb6ffed 100644
--- a/modules/ve-cite/ve.dm.MWDocumentReferences.js
+++ b/modules/ve-cite/ve.dm.MWDocumentReferences.js
@@ -55,14 +55,33 @@ ve.dm.MWDocumentReferences.static.refsForDoc = function ( doc ) {
  */
 ve.dm.MWDocumentReferences.prototype.getGroupRefsByParents = function ( groupName ) {
 	const nodeGroup = this.doc.getInternalList().getNodeGroup( groupName );
-	return ( nodeGroup ? nodeGroup.indexOrder : [] )
-		.reduce( ( acc, index ) => {
-			const node = nodeGroup.firstNodes[ index ];
-			const extendsRef = node.element.attributes.extendsRef || '';
-			if ( acc[ extendsRef ] === undefined ) {
-				acc[ extendsRef ] = [];
-			}
-			acc[ extendsRef ].push( node );
-			return acc;
-		}, {} );
+	const indexOrder = ( nodeGroup ? nodeGroup.indexOrder : [] );
+	// Compile a list of all top-level node names so that we can handle orphans
+	// while keeping them in document order.
+	const seenTopLevelNames = new Set(
+		indexOrder
+			.map( ( index ) => nodeGroup.firstNodes[ index ] )
+			.filter( ( node ) => !node.element.attributes.extendsRef )
+			.map( ( node ) => node.element.attributes.listKey )
+			.filter( ( listKey ) => listKey )
+	);
+	// Group nodes by parent ref, while iterating in order of document appearance.
+	return indexOrder.reduce( ( acc, index ) => {
+		const node = nodeGroup.firstNodes[ index ];
+		let extendsRef = node.element.attributes.extendsRef || '';
+
+		if ( !seenTopLevelNames.has( extendsRef ) ) {
+			// Promote orphaned subrefs to become top-level refs.
+			// TODO: Ideally this would be handled by creating placeholder error
+			// nodes as is done by the renderer.
+			extendsRef = '';
+		}
+
+		if ( acc[ extendsRef ] === undefined ) {
+			acc[ extendsRef ] = [];
+		}
+		acc[ extendsRef ].push( node );
+
+		return acc;
+	}, {} );
 };