1 files changed, 9 insertions, 3 deletions
diff --git a/feed/note-page.js b/feed/note-page.js
index 3145f14..89b2f43 100644
--- a/feed/note-page.js
+++ b/feed/note-page.js
@@ -126,6 +126,12 @@ function nameOf(data, pk) {
   try { const m = JSON.parse(p.content); return { name: m.display_name || m.name || null, picture: m.picture || null }; } catch { return {}; }
 }
 
+// index.html carries the site's own share tags between these markers; a
+// rendered page drops them for its own (crawlers take the first of a pair).
+// The site's picture stays as the stand-in for a page that has none.
+export const siteTagsOut = (html) => html.replace(/<!--site-tags-->[\s\S]*?<!--\/site-tags-->\n?/, '');
+export const siteImage = (origin) => (origin ? origin + '/og-image.png' : '');
+
 // The app's index.html with the thread and its preview tags in the head.
 export function renderNotePage(html, data, ref, origin) {
   const focus = [data.root, ...data.replies].find((e) => e.id === ref.id) || data.root;
@@ -141,13 +147,13 @@ export function renderNotePage(html, data, ref, origin) {
     desc ? `<meta property="og:description" content="${esc(desc)}">` : '',
     desc ? `<meta name="description" content="${esc(desc)}">` : '',
     origin ? `<meta property="og:url" content="${esc(origin + '/' + (ref.path || ''))}">` : '',
-    image ? `<meta property="og:image" content="${esc(image)}">` : '',
-    `<meta name="twitter:card" content="${image && image !== who.picture ? 'summary_large_image' : 'summary'}">`,
+    image || siteImage(origin) ? `<meta property="og:image" content="${esc(image || siteImage(origin))}">` : '',
+    `<meta name="twitter:card" content="${!image || image !== who.picture ? 'summary_large_image' : 'summary'}">`,
     // the author's face starts downloading with the page, not after the app boots
     who.picture && /^https:\/\//.test(who.picture) ? `<link rel="preload" as="image" href="${esc(who.picture)}">` : '',
     `<script type="application/json" id="boot-thread">${scriptJson(data)}</script>`,
   ].filter(Boolean).join('\n');
-  let out = html.replace(/<title>[^<]*<\/title>/i, `<title>${esc(title)}</title>`);
+  let out = siteTagsOut(html).replace(/<title>[^<]*<\/title>/i, `<title>${esc(title)}</title>`);
   out = out.includes('</head>') ? out.replace('</head>', head + '\n</head>') : head + out;
   return out;
 }