From 8973fd814b8c9887140bd5a3a6f6e7fc1adf5daa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martynas=20Jusevi=C4=8Dius?= <martynas@atomgraph.com>
Date: Wed, 5 Aug 2026 15:25:59 +0200
Subject: [PATCH] Rebuild annotation overlay on demand in rdfae:show-overlay

The overlay is a render-once singleton, but a host that re-renders the page
DOM (or disposes it as a Bootstrap modal, as LinkedDataHub does via its
generic modal teardown) can remove it between invocations. show-overlay then
passed an empty node to rdfae:show-at (element(), exactly one), throwing a
SaxonJS cardinality error on the next right-click. Ensure the overlay exists
before positioning it.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 src/overlay.xsl | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/overlay.xsl b/src/overlay.xsl
index 534b80f..cd076d8 100644
--- a/src/overlay.xsl
+++ b/src/overlay.xsl
@@ -257,6 +257,13 @@ version="3.0">
         <xsl:param name="event"/>
         <xsl:param name="in-scope-subject" as="xs:string?" select="()"/>
 
+        <!-- the overlay is a render-once singleton, but a host may re-render the page
+             DOM (or dispose it as a modal) between invocations; rebuild on demand so
+             show-at always has an element to position -->
+        <xsl:if test="empty(id($rdfae:overlay-id, ixsl:page()))">
+            <xsl:call-template name="rdfae:init-overlay"/>
+        </xsl:if>
+
         <xsl:call-template name="rdfae:show-at">
             <xsl:with-param name="element" select="id($rdfae:overlay-id, ixsl:page())"/>
             <xsl:with-param name="event" select="$event"/>