From f95769ae0bc4c024607cf88d14f2498234ac6f87 Mon Sep 17 00:00:00 2001
From: dbrianwalton <dbrianwalton@gmail.com>
Date: Mon, 19 May 2025 15:51:34 -0400
Subject: [PATCH] FITB: Sanitize xml:id and label from copied
 exercise/statement children being used in automatic static solutions. Issue
 #2516

---
 xsl/pretext-runestone-static.xsl | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/xsl/pretext-runestone-static.xsl b/xsl/pretext-runestone-static.xsl
index 434d13f04d..2357e57d8c 100644
--- a/xsl/pretext-runestone-static.xsl
+++ b/xsl/pretext-runestone-static.xsl
@@ -983,6 +983,18 @@ along with PreTeXt.  If not, see <http://www.gnu.org/licenses/>.
     </xsl:copy>
 </xsl:template>
 
+<!-- Don't duplicate xml:id. Nobody should point into the solution. -->
+<!-- Note that any internal link references will point to the original not the copy -->
+<xsl:template match="@xml:id" mode="fillin-solution"/>
+
+<!-- Append to a label -->
+<xsl:template match="@label" mode="fillin-solution">
+    <xsl:attribute name="label">
+        <xsl:value-of select="."/>
+        <xsl:text>-fitb-solution</xsl:text>
+    </xsl:attribute>
+</xsl:template>
+
 <xsl:template match="statement" mode="fillin-solution">
     <xsl:variable name="exercise" select=".."/>
     <solution>