Enable Filters: a folder moved while filters are off is followed by the filter put aside, and Cmd+L still brings it back (follow-up to #2709)

crates/engine/src/cmd/browse.rs

@@ -484,13 +484,17 @@ pub(crate) fn follow_folder(s: &mut Session, from: &str, to: &str) {
     follow_library_folder(&mut s.filter.library_folder, from, to);
     if let Some(f) = s.shelved_filter.as_mut() {
         follow_library_folder(&mut f.library_folder, from, to);
+        follow_library_folder(&mut f.folder, from, to);
     }
     if let Some(b) = &mut s.browse
         && let Ok(rel) = Path::new(&b.path).strip_prefix(from)
     {
         b.path = Path::new(to).join(rel).to_string_lossy().to_string();
-        let f = b.path.clone();
-        s.filter.folder = Some(f);
+        // with filters off the filter stays empty: Cmd+L brings back the one put aside
+        if s.shelved_filter.is_none() {
+            let f = b.path.clone();
+            s.filter.folder = Some(f);
+        }
     }
 }
 

crates/engine/src/lib.rs

@@ -1383,6 +1383,8 @@ mod tests_segment;
 #[cfg(test)]
 mod tests_settings_files;
 #[cfg(test)]
+mod tests_shelved_folder;
+#[cfg(test)]
 mod tests_slide;
 #[cfg(test)]
 mod tests_slideshow_export;

crates/engine/src/tests_shelved_folder.rs

@@ -0,0 +1,69 @@
+//! A filter Enable Filters (Cmd+L) put aside and a folder moved on disk meanwhile: switched back
+//! on, the filter is the one put aside, and a folder it names is where the folder went.
+
+use lightcraft_catalog::{Op, Photo, Source};
+use serde_json::json;
+
+use crate::Session;
+
+fn add(s: &mut Session, path: &str, rating: u8) {
+    let id = s.catalog.alloc_photo_id();
+    let mut p = Photo::new(id, Source::File { path: path.into() }, "x.jpg", "JPEG", 60, 40, "2026-01-01T10:00:00");
+    p.rating = rating;
+    s.catalog.apply(Op::AddPhoto { photo: Box::new(p) }).unwrap();
+}
+
+/// A scratch folder that goes away with the test, however it ends.
+struct Scratch(std::path::PathBuf);
+
+impl Scratch {
+    fn new(tag: &str) -> Scratch {
+        let dir = std::env::temp_dir().join(format!("lc-shelved-{tag}-{}", std::process::id()));
+        let _ = std::fs::remove_dir_all(&dir);
+        std::fs::create_dir_all(dir.join("trip")).unwrap();
+        std::fs::create_dir_all(dir.join("archive")).unwrap();
+        Scratch(dir)
+    }
+    fn path(&self, rel: &str) -> String {
+        self.0.join(rel).components().collect::<std::path::PathBuf>().to_string_lossy().to_string()
+    }
+}
+
+impl Drop for Scratch {
+    fn drop(&mut self) {
+        let _ = std::fs::remove_dir_all(&self.0);
+    }
+}
+
+#[test]
+fn a_folder_in_the_filter_put_aside_follows_a_move() {
+    let dir = Scratch::new("filter");
+    let (trip, archive) = (dir.path("trip"), dir.path("archive"));
+    let mut s = Session::new();
+    add(&mut s, &format!("{trip}/a.jpg"), 0);
+    add(&mut s, &dir.path("elsewhere.jpg"), 0);
+    s.execute("library.filter", &json!({"folder": trip})).unwrap();
+    assert_eq!(s.visible().len(), 1, "the filter hides a photo, or a stale folder would look alike");
+    s.execute("library.toggleFilters", &json!({})).unwrap();
+    s.execute("folder.move", &json!({"path": trip, "into": archive})).unwrap();
+    let r = s.execute("library.toggleFilters", &json!({})).unwrap();
+    assert_eq!(r["enabled"], json!(true));
+    assert_eq!(s.filter.folder.as_deref(), Some(dir.path("archive/trip").as_str()), "the folder where it went");
+    assert_eq!(s.visible().len(), 1, "the moved photo, as before the move");
+}
+
+#[test]
+fn moving_the_browsed_folder_while_off_brings_back_the_filter_put_aside() {
+    let dir = Scratch::new("browse");
+    let (trip, archive) = (dir.path("trip"), dir.path("archive"));
+    let mut s = Session::new();
+    s.execute("library.browse", &json!({"path": trip})).unwrap();
+    s.execute("library.filter", &json!({"rating": 4})).unwrap();
+    let set = s.filter.clone();
+    s.execute("library.toggleFilters", &json!({})).unwrap();
+    s.execute("folder.move", &json!({"path": trip, "into": archive})).unwrap();
+    assert!(s.filters_off(), "still off after the move");
+    let r = s.execute("library.toggleFilters", &json!({})).unwrap();
+    assert_eq!(r["enabled"], json!(true), "Cmd+L turns filtering back on");
+    assert_eq!(s.filter, set, "the stars put aside, nothing added");
+}