Preserve thread names during rollout migration (#39273)

## Why

Legacy threads and paginated threads read their displayed names from different metadata. Moving a rollout to paginated history must carry over its legacy-visible name so renamed threads do not lose it.

## What changed

- Load legacy indexed names once for an apply run.
- When promoting a thread, preserve an existing canonical name or copy its distinct legacy title, falling back to the legacy name index.
- Repair missing names when migration encounters an already-paginated rollout.

## Testing

Added migration tests covering preservation from both legacy name sources and repair on a rerun.

GitOrigin-RevId: 5fc526570b1cf358a159ef174c159ac091ccc40f

codex-rs/state/src/runtime/threads.rs

@@ -61,12 +61,31 @@ WHERE threads.id = ?
             .transpose()
     }
 
-    /// Permanently promote a thread to paginated history without changing metadata or recency.
+    /// Permanently promote a thread, preserving its canonical name or a legacy-visible fallback.
-    pub async fn mark_thread_paginated(&self, thread_id: ThreadId) -> anyhow::Result<bool> {
+    pub async fn mark_thread_paginated(
-        let result = sqlx::query("UPDATE threads SET history_mode = 'paginated' WHERE id = ?")
+        &self,
-            .bind(thread_id.to_string())
+        thread_id: ThreadId,
-            .execute(self.pool.as_ref())
+        legacy_name: Option<&str>,
-            .await?;
+    ) -> anyhow::Result<bool> {
+        // Legacy threads display `title`, then fall back to the name index. Paginated threads
+        // display `name`; `title` remains derived metadata used for search. Preserve an existing
+        // `name`, otherwise carry over the legacy display name.
+        let result = sqlx::query(
+            r#"
+UPDATE threads
+SET
+    history_mode = 'paginated',
+    name = CASE
+        WHEN name IS NULL OR trim(name) = '' THEN ?
+        ELSE name
+    END
+WHERE id = ?
+            "#,
+        )
+        .bind(legacy_name)
+        .bind(thread_id.to_string())
+        .execute(self.pool.as_ref())
+        .await?;
         Ok(result.rows_affected() > 0)
     }
     pub async fn get_thread_memory_mode(&self, id: ThreadId) -> anyhow::Result<Option<String>> {
@@ -1594,7 +1613,7 @@ mod tests {
 
         assert!(
             runtime
-                .mark_thread_paginated(thread_id)
+                .mark_thread_paginated(thread_id, /*legacy_name*/ None)
                 .await
                 .expect("mark paginated history")
         );

codex-rs/thread-store/src/local/rollout_migration.rs

@@ -8,6 +8,7 @@
 //! recoverable paginated rollout. Once the rollout path is replaced, the durable `.pending`
 //! journal must be enough for a later migration run to finish SQLite recovery safely.
 
+use std::collections::HashMap;
 use std::path::Path;
 use std::path::PathBuf;
 use std::time::Duration;
@@ -32,6 +33,7 @@ use tokio::io::BufWriter;
 use tokio::time::Instant;
 
 use super::LocalThreadStore;
+use super::helpers::distinct_thread_metadata_title;
 use super::thread_history;
 use super::thread_history::ProjectedRolloutLine;
 use super::thread_history::RolloutProjectionStep;
@@ -297,12 +299,24 @@ impl LocalThreadStore {
                     .is_some_and(|thread_id| pending_thread_ids.contains(&thread_id))
             });
         }
+        // The name index is global, so read it once before either migrating or repairing names.
+        let legacy_names = if options.mode == RolloutMigrationMode::Apply {
+            let thread_ids = paths
+                .iter()
+                .filter_map(|path| thread_id_from_rollout_filename(path))
+                .collect();
+            codex_rollout::find_thread_names_by_ids(&self.config.codex_home, &thread_ids)
+                .await
+                .unwrap_or_default()
+        } else {
+            HashMap::new()
+        };
         let total_paths = paths.len();
         let mut report = RolloutMigrationReport::default();
 
         for (index, path) in paths.into_iter().enumerate() {
             let outcome = self
-                .migrate_rollout_path(path, &options, &mut limiter)
+                .migrate_rollout_path(path, &options, &legacy_names, &mut limiter)
                 .await?;
             let outcome_status = outcome.as_ref().map(|outcome| outcome.status);
             if let Some(outcome) = outcome {
@@ -322,6 +336,7 @@ impl LocalThreadStore {
         &self,
         mut path: PathBuf,
         options: &RolloutMigrationOptions,
+        legacy_names: &HashMap<ThreadId, String>,
         limiter: &mut RolloutMigrationRateLimiter,
     ) -> ThreadStoreResult<Option<RolloutMigrationOutcome>> {
         let metadata = match codex_rollout::read_session_meta_line(&path).await {
@@ -380,7 +395,13 @@ impl LocalThreadStore {
             let result = if pending_published_migration {
                 let _live_writer_guard = self.live_writer_locks.lock(thread_id).await;
                 match self
-                    .recover_published_migration(thread_id, &path, &journal_path, limiter)
+                    .recover_published_migration(
+                        thread_id,
+                        &path,
+                        &journal_path,
+                        legacy_names,
+                        limiter,
+                    )
                     .await
                 {
                     Ok(recovered_path) => {
@@ -399,6 +420,9 @@ impl LocalThreadStore {
                     Err(error) => Err(error),
                 }
             } else {
+                if options.mode == RolloutMigrationMode::Apply {
+                    self.promote_legacy_name(thread_id, legacy_names).await?;
+                }
                 Ok(RolloutMigrationStatus::AlreadyPaginated)
             };
             let bytes_processed = limiter.bytes_processed.saturating_sub(bytes_before);
@@ -438,7 +462,7 @@ impl LocalThreadStore {
         };
         let bytes_before = limiter.bytes_processed;
         let result = match self
-            .migrate_one_rollout(thread_id, &path, &journal_path, kind, limiter)
+            .migrate_one_rollout(thread_id, &path, &journal_path, kind, legacy_names, limiter)
             .await
         {
             Ok(()) => Ok(RolloutMigrationStatus::Migrated),
@@ -470,6 +494,7 @@ impl LocalThreadStore {
         rollout_path: &Path,
         journal_path: &Path,
         kind: RolloutMigrationKind,
+        legacy_names: &HashMap<ThreadId, String>,
         limiter: &mut RolloutMigrationRateLimiter,
     ) -> ThreadStoreResult<()> {
         if let Some(state_db) = &self.state_db
@@ -627,7 +652,7 @@ impl LocalThreadStore {
                 .map_err(migration_error)?;
         }
         sync_parent_directory(rollout_path).await?;
-        self.finish_published_migration(thread_id, journal_path)
+        self.finish_published_migration(thread_id, journal_path, legacy_names)
             .await
     }
 
@@ -798,6 +823,7 @@ impl LocalThreadStore {
         thread_id: ThreadId,
         rollout_path: &Path,
         journal_path: &Path,
+        legacy_names: &HashMap<ThreadId, String>,
         limiter: &mut RolloutMigrationRateLimiter,
     ) -> ThreadStoreResult<PathBuf> {
         let _writer_guard = self.writer_lock_coordinator.acquire(thread_id)?;
@@ -838,7 +864,7 @@ impl LocalThreadStore {
         if let Some(decompressed_path) = decompressed_path.as_ref() {
             remove_file_if_present(decompressed_path).await?;
         }
-        self.finish_published_migration(thread_id, journal_path)
+        self.finish_published_migration(thread_id, journal_path, legacy_names)
             .await?;
         Ok(rollout_path.to_path_buf())
     }
@@ -870,23 +896,52 @@ impl LocalThreadStore {
         &self,
         thread_id: ThreadId,
         journal_path: &Path,
+        legacy_names: &HashMap<ThreadId, String>,
     ) -> ThreadStoreResult<()> {
-        if let Some(state_db) = &self.state_db
+        self.promote_legacy_name(thread_id, legacy_names).await?;
-            && !state_db
-                .mark_thread_paginated(thread_id)
-                .await
-                .map_err(migration_error)?
-        {
-            return Err(migration_error(format!(
-                "thread {thread_id} is missing its SQLite metadata"
-            )));
-        }
         tokio::fs::remove_file(journal_path)
             .await
             .map_err(migration_error)?;
         sync_parent_directory(journal_path).await
     }
 
+    async fn promote_legacy_name(
+        &self,
+        thread_id: ThreadId,
+        legacy_names: &HashMap<ThreadId, String>,
+    ) -> ThreadStoreResult<()> {
+        if let Some(state_db) = &self.state_db {
+            let metadata = state_db
+                .get_thread(thread_id)
+                .await
+                .map_err(migration_error)?
+                .ok_or_else(|| {
+                    migration_error(format!("thread {thread_id} is missing its SQLite metadata"))
+                })?;
+            if metadata.history_mode == ThreadHistoryMode::Paginated
+                && metadata
+                    .name
+                    .as_deref()
+                    .is_some_and(|name| !name.trim().is_empty())
+            {
+                return Ok(());
+            }
+            let legacy_name = distinct_thread_metadata_title(&metadata)
+                .or_else(|| legacy_names.get(&thread_id).cloned())
+                .filter(|name| !name.trim().is_empty());
+            if !state_db
+                .mark_thread_paginated(thread_id, legacy_name.as_deref())
+                .await
+                .map_err(migration_error)?
+            {
+                return Err(migration_error(format!(
+                    "thread {thread_id} is missing its SQLite metadata"
+                )));
+            }
+        }
+        Ok(())
+    }
+
     async fn project_rollout_in_batches(
         &self,
         thread_id: ThreadId,

codex-rs/thread-store/src/local/rollout_migration_tests.rs

@@ -56,13 +56,17 @@ use super::thread_history;
 use super::write_migration_journal;
 use crate::ItemSortKey;
 use crate::ListItemsParams;
+use crate::ListThreadsParams;
 use crate::ListTurnsParams;
 use crate::LoadThreadHistoryParams;
 use crate::SortDirection;
 use crate::StoredTurnItemsView;
+use crate::ThreadMetadataPatch;
+use crate::ThreadSortKey;
 use crate::ThreadStore;
 use crate::ThreadStoreError;
 use crate::TurnPage;
+use crate::UpdateThreadMetadataParams;
 use crate::local::test_support::test_config;
 
 const TIMESTAMP: &str = "2025-01-03T12:00:00Z";
@@ -1766,6 +1770,137 @@ async fn migration_migrates_archived_rollouts_without_unarchiving_them() {
     assert_eq!(turns.turns[0].items.len(), 2);
 }
 
+#[tokio::test]
+async fn migration_preserves_legacy_displayed_thread_names() {
+    let home = TempDir::new().expect("create Codex home");
+    let title_thread_id = ThreadId::new();
+    write_rollout(
+        home.path(),
+        title_thread_id,
+        SessionSource::Cli,
+        vec![user_message("title question")],
+    );
+    let index_thread_id = ThreadId::new();
+    write_rollout(
+        home.path(),
+        index_thread_id,
+        SessionSource::Cli,
+        vec![user_message("index question")],
+    );
+    let store = indexed_store(home.path()).await;
+    store
+        .update_thread_metadata(UpdateThreadMetadataParams {
+            thread_id: title_thread_id,
+            patch: ThreadMetadataPatch {
+                name: Some(Some("renamed title".to_string())),
+                ..Default::default()
+            },
+            include_archived: false,
+        })
+        .await
+        .expect("rename legacy thread");
+    codex_rollout::append_thread_name(home.path(), title_thread_id, "stale index title")
+        .await
+        .expect("write stale legacy index name");
+    codex_rollout::append_thread_name(home.path(), index_thread_id, "indexed title")
+        .await
+        .expect("write legacy index name");
+
+    store
+        .migrate_rollouts(apply_options())
+        .await
+        .expect("migrate named rollouts");
+
+    let page = store
+        .list_threads(ListThreadsParams {
+            page_size: 10,
+            cursor: None,
+            sort_key: ThreadSortKey::CreatedAt,
+            sort_direction: SortDirection::Desc,
+            allowed_sources: Vec::new(),
+            model_providers: None,
+            cwd_filters: None,
+            section: None,
+            project_id: None,
+            archived: false,
+            search_term: None,
+            relation_filter: None,
+            use_state_db_only: true,
+        })
+        .await
+        .expect("list migrated threads");
+    let title_thread = page
+        .items
+        .iter()
+        .find(|thread| thread.thread_id == title_thread_id)
+        .expect("renamed title thread");
+    let index_thread = page
+        .items
+        .iter()
+        .find(|thread| thread.thread_id == index_thread_id)
+        .expect("indexed title thread");
+
+    assert_eq!(title_thread.name.as_deref(), Some("renamed title"));
+    assert_eq!(index_thread.name.as_deref(), Some("indexed title"));
+}
+
+#[tokio::test]
+async fn migration_repairs_a_missing_paginated_name_when_rerun() {
+    let home = TempDir::new().expect("create Codex home");
+    let thread_id = ThreadId::new();
+    write_rollout(
+        home.path(),
+        thread_id,
+        SessionSource::Cli,
+        vec![user_message("question")],
+    );
+    let store = indexed_store(home.path()).await;
+    store
+        .update_thread_metadata(UpdateThreadMetadataParams {
+            thread_id,
+            patch: ThreadMetadataPatch {
+                name: Some(Some("renamed title".to_string())),
+                ..Default::default()
+            },
+            include_archived: false,
+        })
+        .await
+        .expect("rename legacy thread");
+    store
+        .migrate_rollouts(apply_options())
+        .await
+        .expect("migrate named rollout");
+    let state_db = store.state_db().await.expect("state runtime");
+    state_db
+        .update_thread_title(thread_id, "question")
+        .await
+        .expect("restore derived title");
+    state_db
+        .update_thread_name(thread_id, /*name*/ None)
+        .await
+        .expect("clear migrated name");
+
+    let report = store
+        .migrate_rollouts(apply_options())
+        .await
+        .expect("repair migrated name");
+
+    assert_eq!(
+        report.outcomes[0].status,
+        RolloutMigrationStatus::AlreadyPaginated
+    );
+    assert_eq!(
+        state_db
+            .get_thread(thread_id)
+            .await
+            .expect("read repaired metadata")
+            .expect("repaired thread")
+            .name
+            .as_deref(),
+        Some("renamed title")
+    );
+}
+
 #[cfg(unix)]
 #[tokio::test]
 async fn decompression_temporaries_are_owner_only() {