Move old items' http artwork to https too, for hosts the feed no longer names (#110)

The first pass only asked the hosts the feed's current body names. IGN's feed kept five 2009
items with artwork on assets1/assets2.ignimgs.com, which its feed no longer mentions, so they
stayed on http. A scan now also asks, once per host, the hosts of the feed's stored http
artwork (Db::http_images).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/db.rs

@@ -791,6 +791,20 @@ impl Db {
         Ok(())
     }
 
+    /// A feed's stored artwork still on http, items' and its own: hosts a feed no longer names
+    /// keep their old items' artwork on http otherwise (IGN's 2009 items, #110).
+    pub async fn http_images(&self, feed_id: &str) -> Result<Vec<String>> {
+        self.rows(
+            "SELECT DISTINCT image FROM entries WHERE feed_id = $1 AND image LIKE 'http://%'
+             UNION SELECT image FROM feeds WHERE id = $1 AND image LIKE 'http://%'",
+            vec![feed_id.into()],
+        )
+        .await?
+        .iter()
+        .map(|r| Ok(r.try_get("", "image")?))
+        .collect()
+    }
+
     /// Rewrites a feed's stored artwork on `host` from http to https, once the host is known to
     /// serve it there (`feed::prefer_https`), for the items a scan does not write again.
     pub async fn secure_images(&self, feed_id: &str, host: &str) -> Result<()> {
@@ -2056,6 +2070,9 @@ mod tests {
                 ('f','1',0,'http://a.example/1.jpg'),('f','2',0,'http://b.example/2.jpg'),('g','3',0,'http://a.example/3.jpg');",
         ).await
         .unwrap();
+        let mut old = db.http_images("f").await.unwrap();
+        old.sort();
+        assert_eq!(old, ["http://a.example/1.jpg", "http://a.example/logo.png", "http://b.example/2.jpg"]);
         db.secure_images("f", "a.example").await.unwrap();
         assert_eq!(db.feed_summary("f").await.unwrap().image.as_deref(), Some("https://a.example/logo.png"));
         assert!(db.names_image("https://a.example/1.jpg").await.unwrap());

src/main.rs

@@ -1430,7 +1430,11 @@ async fn scan_one(
     if let Some(art) = &parsed.image {
         parsed.image = Some(feed::prefer_https(&ctx.client, art, &mut secure).await);
     }
-    // Items stored before, which a scan does not write again, move with their host.
+    // Items stored before, which a scan does not write again, move with their host, and a host
+    // only they still name is asked too.
+    for art in ctx.db.http_images(id).await? {
+        feed::prefer_https(&ctx.client, &art, &mut secure).await;
+    }
     for (host, ok) in &secure {
         if *ok {
             ctx.db.secure_images(id, host).await?;