From 1d301c0b1f068795eb6d5f838e517813dd50121c Mon Sep 17 00:00:00 2001
From: Andrew Scholer <ascholer@chemeketa.edu>
Date: Mon, 31 Aug 2026 10:33:43 -0700
Subject: [PATCH] HTML: provide alt text for image data files

---
 xsl/pretext-runestone.xsl | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/xsl/pretext-runestone.xsl b/xsl/pretext-runestone.xsl
index e97f299a0..cf052c8d5 100644
--- a/xsl/pretext-runestone.xsl
+++ b/xsl/pretext-runestone.xsl
@@ -2839,6 +2839,16 @@ along with PreTeXt.  If not, see <http://www.gnu.org/licenses/>.
                         <xsl:text>;base64,</xsl:text>
                         <xsl:value-of select="$image-b64-elt/@pi:base64"/>
                     </xsl:attribute>
+                    <xsl:attribute name="alt">
+                        <xsl:choose>
+                            <xsl:when test="image/shortdescription">
+                                <xsl:value-of select="image/shortdescription"/>
+                            </xsl:when>
+                            <xsl:otherwise>
+                                <xsl:value-of select="@filename"/>
+                            </xsl:otherwise>
+                        </xsl:choose>
+                    </xsl:attribute>
                 </img>
             </xsl:when>
             <!-- text, an authored toy example, or a serious external file -->