fix(php-transformer): apply the native lightbox to gallery card triggers

php-transformer/src/HtmlToBlocks/HtmlCompilation.php

@@ -9744,6 +9744,13 @@ public function convertLinkWrapperGroup(DOMElement $anchor, array &$fallbacks):
         }
 
         $linkAttrs = $this->linkPropagationAttributes($anchor);
+        // A gallery thumbnail wraps its image, and often a caption overlay, in
+        // a lightbox trigger. That link is the viewer, not a destination, so
+        // core's native lightbox replaces it rather than propagating an href
+        // that would navigate away from the page.
+        if ( $this->imageLinkOpensNativeLightbox($anchor) && $this->enableNativeLightboxOnImages($children) ) {
+            return $this->createBlock('core/group', $this->styleResolver->presentationAttributes($anchor), $children, $anchor);
+        }
         if ( array() !== $linkAttrs && ! $this->propagateLinkWrapper($children, $linkAttrs) ) {
             $this->recordDroppedLinkWrapper($anchor);
         }
@@ -9902,6 +9909,39 @@ private function propagateLinkWrapper(array &$blocks, array $linkAttrs): bool
      * @param array<string, mixed> $block
      * @param array<string, string> $linkAttrs
      */
+    /**
+     * Opt every unlinked image inside a lightbox trigger into core's native
+     * lightbox. An image that already carries its own link keeps it, because
+     * core suppresses its lightbox when a link is present.
+     *
+     * @param array<int, array<string, mixed>> $blocks
+     */
+    private function enableNativeLightboxOnImages(array &$blocks): bool
+    {
+        $enabled = false;
+        foreach ( $blocks as $index => $block ) {
+            if ( ! is_array($block) ) {
+                continue;
+            }
+
+            if ( 'core/image' === (string) ($block['blockName'] ?? '') ) {
+                $attrs = is_array($block['attrs'] ?? null) ? $block['attrs'] : array();
+                if ( '' === (string) ($attrs['href'] ?? '') ) {
+                    $attrs['lightbox'] = array( 'enabled' => true );
+                    $blocks[ $index ] = $this->rebuildBlock($block, $attrs);
+                    $enabled = true;
+                }
+                continue;
+            }
+
+            if ( is_array($block['innerBlocks'] ?? null) && $this->enableNativeLightboxOnImages($blocks[ $index ]['innerBlocks']) ) {
+                $enabled = true;
+            }
+        }
+
+        return $enabled;
+    }
+
     private function propagateLinkOntoImage(array &$block, array $linkAttrs): bool
     {
         $attrs = is_array($block['attrs'] ?? null) ? $block['attrs'] : array();

php-transformer/tests/unit/image-lightbox-link-projection.php

@@ -86,6 +86,37 @@
     $nonImage
 );
 
+// A gallery card: the trigger wraps the image plus a caption overlay, so the
+// link is propagated as a card-link wrapper rather than a bare image link.
+$galleryCard = $transform(
+    '<main><div class="galleryInnerImageHolder">'
+    . '<a href="/uploads/img-1631_orig.jpeg" rel="lightbox[gallery219311460416557837]" title="Yosemite" class="w-fancybox">'
+    . '<img src="/media/img-1631.jpeg" class="galleryImage" width="800" height="600" alt="Yosemite">'
+    . '<div class="galleryCaptionHolder"><div class="galleryCaptionInnerText">Yosemite National Park, USA</div></div>'
+    . '</a></div></main>'
+);
+$assert(
+    str_contains($galleryCard, '"lightbox":{"enabled":true}'),
+    'a gallery card whose trigger also wraps a caption still opts into the native lightbox',
+    $galleryCard
+);
+$assert(
+    ! str_contains($galleryCard, '"linkDestination"') && ! str_contains($galleryCard, 'href="/uploads/img-1631_orig.jpeg"'),
+    'the gallery card trigger link is not propagated onto the image',
+    $galleryCard
+);
+
+// A real card link wrapping an image plus copy keeps propagating its link.
+$cardLink = $transform(
+    '<main><div><a href="/research.html"><img src="/media/thumb.jpg" width="800" height="600" alt="R">'
+    . '<div><p>Read the research</p></div></a></div></main>'
+);
+$assert(
+    ! str_contains($cardLink, '"lightbox"') && str_contains($cardLink, '/research.html'),
+    'an ordinary card link keeps propagating its destination',
+    $cardLink
+);
+
 if ( 0 < $failures ) {
     fwrite(STDERR, "image lightbox link projection FAILED: {$passes} passed, {$failures} failed\n");
     exit(1);