Redirect manual date edits on a version path to its original (#194)

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

src/database/version_dao.rs

@@ -188,6 +188,15 @@ pub trait VersionDao: Sync + Send {
     /// the original's rel_path (same library when possible).
     fn original_path_of(&mut self, rel_path: &str) -> Result<Option<String>, DbError>;
 
+    /// `(library_id, rel_path)` of the original of the version at
+    /// `(library_id, rel_path)`, when it is a linked version with a live
+    /// original. For per-library writes that must land on the original.
+    fn original_location_of(
+        &mut self,
+        library_id: i32,
+        rel_path: &str,
+    ) -> Result<Option<(i32, String)>, DbError>;
+
     /// Which of `hashes` are versions of something.
     fn version_hashes_among(&mut self, hashes: &[String]) -> Result<HashSet<String>, DbError>;
 
@@ -304,13 +313,25 @@ pub fn canonical_rel_path(
     library_id: Option<i32>,
     rel_path: &str,
 ) -> QueryResult<Option<String>> {
+    Ok(canonical_location(conn, library_id, rel_path)?.map(|(_, p)| p))
+}
+
+/// [`canonical_rel_path`] with the original's library too, for callers that
+/// write per-library rows (the manual date lives on the `image_exif` row).
+pub fn canonical_location(
+    conn: &mut SqliteConnection,
+    library_id: Option<i32>,
+    rel_path: &str,
+) -> QueryResult<Option<(i32, String)>> {
     #[derive(QueryableByName)]
     struct Row {
+        #[diesel(sql_type = Integer)]
+        library_id: i32,
         #[diesel(sql_type = Text)]
         rel_path: String,
     }
     let rows = sql_query(
-        "SELECT o.rel_path AS rel_path FROM image_exif v \
+        "SELECT o.library_id AS library_id, o.rel_path AS rel_path FROM image_exif v \
          JOIN photo_versions pv ON pv.version_hash = v.content_hash \
          JOIN image_exif o ON o.content_hash = pv.original_hash \
          WHERE v.rel_path = ?1 AND (?2 IS NULL OR v.library_id = ?2) \
@@ -323,7 +344,7 @@ pub fn canonical_rel_path(
     .bind::<Text, _>(rel_path)
     .bind::<Nullable<Integer>, _>(library_id)
     .load::<Row>(conn)?;
-    Ok(rows.into_iter().next().map(|r| r.rel_path))
+    Ok(rows.into_iter().next().map(|r| (r.library_id, r.rel_path)))
 }
 
 /// Fold favorites and tags recorded on a version's own path into its
@@ -522,6 +543,19 @@ impl VersionDao for SqliteVersionDao {
         .map_err(|e| DbError::log(DbErrorKind::QueryError, e))
     }
 
+    fn original_location_of(
+        &mut self,
+        library_id: i32,
+        rel_path: &str,
+    ) -> Result<Option<(i32, String)>, DbError> {
+        trace_db_call("query", "original_location_of", |_span| {
+            let mut conn = self.connection.lock().expect("Unable to get VersionDao");
+            canonical_location(&mut conn, Some(library_id), rel_path)
+                .map_err(|e| anyhow::anyhow!("Query error: {}", e))
+        })
+        .map_err(|e| DbError::log(DbErrorKind::QueryError, e))
+    }
+
     fn version_hashes_among(&mut self, hashes: &[String]) -> Result<HashSet<String>, DbError> {
         trace_db_call("query", "version_hashes_among", |_span| {
             #[derive(QueryableByName)]