LR-EDIT-OPTICS-PROFILE: a decode from before a lens profile change never returns to the source cache (CodeRabbit, #3073)

A job's source identity carries the photo's database profile with its content, and Session::accept keeps a loaded
source only when both still match.

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

crates/engine/src/media/quick.rs

@@ -99,6 +99,20 @@ impl QuickJob {
 }
 
 /// What identifies a photo's pixels for caching: its content hash, else its source.
+/// Which decode of a photo a loaded source is: its file's content and, when it has one, its database lens profile
+/// ([`lens_key`]; the decode fits the starting colour through it). A job's source is kept only when this still
+/// matches when the job finishes ([`super::Session::accept`]), so a decode started before a profile change never
+/// returns to the cache after `cmd::lens_refresh` has dropped the photo's sources.
+pub fn source_identity(p: &Photo) -> Hash128 {
+    let mut k = Hasher128::new();
+    k.str(&content_key(p));
+    let lens = lens_key(p);
+    if lens != 0 {
+        k.u64(lens);
+    }
+    k.finish()
+}
+
 pub fn content_key(p: &Photo) -> String {
     match (&p.content_hash, &p.source) {
         (Some(h), _) => h.clone(),

crates/engine/src/media/session.rs

@@ -47,8 +47,8 @@ impl crate::Session {
         // share a result (a view slot showing photo A would otherwise look current for photo B)
         // …and so is the file's content: a file changed on disk (Reload) renders afresh
         let content_key = content_key(&p);
-        let source_key = Hasher128::new().str(&content_key).finish();
-        let content = source_key.0 as u64;
+        let content = Hasher128::new().str(&content_key).finish().0 as u64;
+        let source_key = super::quick::source_identity(&p);
         // Temporary "before" settings must not replace the photo's cached develop hash.
         let settings_hash = if before { settings.hash64() } else { self.media.settings_hashes.get(id, &settings) };
         let salt = self.media.denoise_salt(id, &settings);
@@ -136,7 +136,7 @@ impl crate::Session {
         Some(RenderJob {
             request_id: 0,
             cache_generation: self.media.rendered.generation(),
-            source_key: Some(Hasher128::new().str(&content_key(&p)).finish()),
+            source_key: Some(super::quick::source_identity(&p)),
             photo: id,
             level,
             source,
@@ -191,7 +191,7 @@ impl crate::Session {
         Some(RenderJob {
             request_id: 0,
             cache_generation: self.media.rendered.generation(),
-            source_key: Some(Hasher128::new().str(&content_key(&p)).finish()),
+            source_key: Some(super::quick::source_identity(&p)),
             photo: id,
             level,
             source,
@@ -389,7 +389,7 @@ impl crate::Session {
     /// has wrong is corrected too ([`Self::learn_as_shot_wb`]).
     pub fn accept(&mut self, r: &RenderResult) {
         if let Some(src) = &r.loaded
-            && r.source_key.is_none_or(|key| self.catalog.photo(r.photo).is_some_and(|p| Hasher128::new().str(&content_key(p)).finish() == key))
+            && r.source_key.is_none_or(|key| self.catalog.photo(r.photo).is_some_and(|p| super::quick::source_identity(p) == key))
         {
             if let Some(info) = &src.info {
                 self.learn_as_shot_wb(r.photo, info);

crates/engine/src/media/thumbnail_hash_tests.rs

@@ -88,6 +88,25 @@ fn source_from_before_content_reload_is_not_accepted() {
     s.accept(&old);
     assert_eq!(s.media.source_usage().0, 0);
 }
+/// A decode that started before the photo's database lens profile changed (a lens database arriving, looked up again
+/// by `cmd::lens_refresh`, which drops the photo's sources) never puts its source back in the cache: the source's
+/// colour was fitted through the old profile.
+#[test]
+fn source_from_before_a_lens_profile_change_is_not_accepted() {
+    let mut s = session();
+    s.media.file_loader = Some(Arc::new(|_, _| Ok((Rgb32f::new(8, 8), SourceInfo::default()))));
+    let old = s.thumb_job(PhotoId(1), 256).unwrap().run();
+    assert!(old.loaded.is_some());
+    let lens = lightcraft_develop::EmbeddedLens { source: lightcraft_develop::LensSource::Database, ..Default::default() };
+    s.catalog.apply(Op::SetEmbeddedLens { id: PhotoId(1), lens: Some(Box::new(lens)) }).unwrap();
+    s.media.forget(PhotoId(1));
+    s.accept(&old);
+    assert_eq!(s.media.source_usage().0, 0, "the old decode is dropped");
+    // a decode made with the new profile is kept
+    let new = s.thumb_job(PhotoId(1), 256).unwrap().run();
+    s.accept(&new);
+    assert_ne!(s.media.source_usage().0, 0);
+}
 /// A panic while rendering (here in the decoder) used to end the pool's worker thread without
 /// an answer, so the view that asked showed "Rendering…" forever. It is the job's failure now,
 /// for renders and for stand-ins, answering the request it came from.