fix: session resume — scan all workspaces, skip current empty session

rust/crates/runtime/src/session_control.rs

@@ -93,8 +93,19 @@ impl SessionStore {
     }
 
     pub fn resolve_reference(&self, reference: &str) -> Result<SessionHandle, SessionControlError> {
+        self.resolve_reference_excluding(reference, None)
+    }
+
+    /// Resolve a session reference, optionally excluding a session by ID.
+    /// When the reference is an alias, the excluded session is skipped
+    /// so /resume latest returns the previous session, not the current one.
+    pub fn resolve_reference_excluding(
+        &self,
+        reference: &str,
+        exclude_id: Option<&str>,
+    ) -> Result<SessionHandle, SessionControlError> {
         if is_session_reference_alias(reference) {
-            let latest = self.latest_session()?;
+            let latest = self.latest_session_excluding(exclude_id)?;
             return Ok(SessionHandle {
                 id: latest.id,
                 path: latest.path,
@@ -158,12 +169,45 @@ impl SessionStore {
     }
 
     pub fn latest_session(&self) -> Result<ManagedSessionSummary, SessionControlError> {
-        if let Some(latest) = self.list_sessions()?.into_iter().next() {
+        self.latest_session_excluding(None)
+    }
+
+    /// Find the most recent session, optionally excluding a session by ID
+    /// and skipping sessions with 0 messages. Used by /resume latest to skip
+    /// the current empty session and find the previous session with actual
+    /// conversation history.
+    pub fn latest_session_excluding(
+        &self,
+        exclude_id: Option<&str>,
+    ) -> Result<ManagedSessionSummary, SessionControlError> {
+        let exclude = exclude_id.unwrap_or("");
+        // First: look in the current workspace's session namespace
+        if let Some(latest) = self
+            .list_sessions()?
+            .into_iter()
+            .find(|s| s.id != exclude && s.message_count > 0)
+        {
             return Ok(latest);
         }
-        if let Some(latest) = self.scan_global_sessions()?.into_iter().next() {
+        // Fallback: scan all workspace namespaces under ~/.claw/sessions/
+        // and project-local .claw/sessions/ so /resume latest finds sessions
+        // from other workspaces.
+        if let Some(latest) = self
+            .scan_global_sessions()?
+            .into_iter()
+            .find(|s| s.id != exclude && s.message_count > 0)
+        {
             return Ok(latest);
         }
+        // Distinguish between "no sessions at all" and "sessions exist but
+        // all are empty" so the user gets a clear signal about what to do.
+        let has_any_session = self.list_sessions()?.iter().any(|s| s.id != exclude)
+            || self.scan_global_sessions()?.iter().any(|s| s.id != exclude);
+        if has_any_session {
+            return Err(SessionControlError::Format(format_all_sessions_empty(
+                &self.sessions_root,
+            )));
+        }
         Err(SessionControlError::Format(format_no_managed_sessions(
             &self.sessions_root,
         )))
@@ -204,28 +248,41 @@ impl SessionStore {
         &self,
         reference: &str,
     ) -> Result<LoadedManagedSession, SessionControlError> {
-        match self.load_session(reference) {
-            Ok(loaded) => Ok(loaded),
-            Err(SessionControlError::WorkspaceMismatch { expected, actual })
-                if is_session_reference_alias(reference) =>
+        self.load_session_excluding(reference, None)
+    }
+
+    /// Like `load_session_loose` but also excludes a session by ID.
+    /// Used by /resume latest to skip the current empty session and find
+    /// the previous session with actual conversation history.
+    pub fn load_session_excluding(
+        &self,
+        reference: &str,
+        exclude_id: Option<&str>,
+    ) -> Result<LoadedManagedSession, SessionControlError> {
+        let handle = self.resolve_reference_excluding(reference, exclude_id)?;
+        let session = Session::load_from_path(&handle.path)?;
+        // For alias references, allow cross-workspace resume
+        if is_session_reference_alias(reference) {
+            if let Err(SessionControlError::WorkspaceMismatch {
+                expected: _,
+                actual,
+            }) = self.validate_loaded_session(&handle.path, &session)
             {
-                let handle = self.resolve_reference(reference)?;
-                let session = Session::load_from_path(&handle.path)?;
                 eprintln!(
                     "  Note: resuming session from a different workspace (origin: {})",
                     actual.display()
                 );
-                let _ = expected; // suppress unused warning
-                Ok(LoadedManagedSession {
-                    handle: SessionHandle {
-                        id: session.session_id.clone(),
-                        path: handle.path,
-                    },
-                    session,
-                })
             }
-            Err(other) => Err(other),
+        } else {
+            self.validate_loaded_session(&handle.path, &session)?;
         }
+        Ok(LoadedManagedSession {
+            handle: SessionHandle {
+                id: session.session_id.clone(),
+                path: handle.path,
+            },
+            session,
+        })
     }
 
     pub fn fork_session(
@@ -726,6 +783,16 @@ fn format_no_managed_sessions(sessions_root: &Path) -> String {
     )
 }
 
+fn format_all_sessions_empty(sessions_root: &Path) -> String {
+    let fingerprint_dir = sessions_root
+        .file_name()
+        .and_then(|f| f.to_str())
+        .unwrap_or("<unknown>");
+    format!(
+        "all sessions are empty (0 messages) in .claw/sessions/{fingerprint_dir}/\nThis usually means a fresh `claw` session is running but no messages have been sent yet.\nWait for a response in your other session, then try `--resume {LATEST_SESSION_REFERENCE}` again."
+    )
+}
+
 fn format_legacy_session_missing_workspace_root(
     session_path: &Path,
     workspace_root: &Path,
@@ -1220,6 +1287,114 @@ mod tests {
         fs::remove_dir_all(base).expect("temp dir should clean up");
     }
 
+    #[test]
+    fn latest_session_returns_all_empty_error_when_sessions_exist_but_have_no_messages() {
+        // given — create sessions with 0 messages (empty)
+        let base = temp_dir();
+        fs::create_dir_all(&base).expect("base dir should exist");
+        let store = SessionStore::from_cwd(&base).expect("store should build");
+
+        let empty_handle = store.create_handle("empty-session");
+        Session::new()
+            .with_persistence_path(empty_handle.path.clone())
+            .save_to_path(&empty_handle.path)
+            .expect("empty session should save");
+
+        // when — latest_session should fail with the "all sessions empty" message
+        let result = store.latest_session();
+        assert!(
+            result.is_err(),
+            "latest_session should fail when all sessions are empty"
+        );
+        let err_msg = result.unwrap_err().to_string();
+        assert!(
+            err_msg.contains("all sessions are empty"),
+            "error should mention 'all sessions are empty', got: {err_msg}"
+        );
+        assert!(
+            err_msg.contains("0 messages"),
+            "error should mention '0 messages', got: {err_msg}"
+        );
+
+        fs::remove_dir_all(base).expect("temp dir should clean up");
+    }
+
+    #[test]
+    fn latest_session_excluding_skips_excluded_id_and_returns_previous() {
+        // given — two sessions WITH messages, newest excluded
+        let base = temp_dir();
+        fs::create_dir_all(&base).expect("base dir should exist");
+        let store = SessionStore::from_cwd(&base).expect("store should build");
+        let older = persist_session_via_store(&store, "older work");
+        wait_for_next_millisecond();
+        let newer = persist_session_via_store(&store, "newer work");
+
+        // when — exclude the newest session
+        let latest = store
+            .latest_session_excluding(Some(&newer.session_id))
+            .expect("latest excluding newest should resolve");
+
+        // then — the older session wins because the newest is skipped
+        assert_eq!(
+            latest.id, older.session_id,
+            "excluded id must be skipped, returning the previous session"
+        );
+        fs::remove_dir_all(base).expect("temp dir should clean up");
+    }
+
+    #[test]
+    fn latest_session_filters_out_zero_message_sessions() {
+        // given — one empty (0-message) session and one non-empty session
+        let base = temp_dir();
+        fs::create_dir_all(&base).expect("base dir should exist");
+        let store = SessionStore::from_cwd(&base).expect("store should build");
+
+        let empty_handle = store.create_handle("empty-session");
+        Session::new()
+            .with_persistence_path(empty_handle.path.clone())
+            .save_to_path(&empty_handle.path)
+            .expect("empty session should save");
+        wait_for_next_millisecond();
+        let non_empty = persist_session_via_store(&store, "real conversation");
+
+        // when
+        let latest = store.latest_session().expect("latest should resolve");
+
+        // then — the non-empty session wins; the 0-message one is filtered out
+        assert_eq!(
+            latest.id, non_empty.session_id,
+            "0-message session must be filtered out, non-empty session wins"
+        );
+        assert!(
+            latest.message_count > 0,
+            "resolved session must have messages"
+        );
+        fs::remove_dir_all(base).expect("temp dir should clean up");
+    }
+
+    #[test]
+    fn resolve_reference_excluding_latest_skips_excluded_id() {
+        // given — two sessions WITH messages
+        let base = temp_dir();
+        fs::create_dir_all(&base).expect("base dir should exist");
+        let store = SessionStore::from_cwd(&base).expect("store should build");
+        let older = persist_session_via_store(&store, "older work");
+        wait_for_next_millisecond();
+        let newer = persist_session_via_store(&store, "newer work");
+
+        // when — resolve the "latest" alias while excluding the newest session
+        let handle = store
+            .resolve_reference_excluding("latest", Some(&newer.session_id))
+            .expect("latest alias excluding newest should resolve");
+
+        // then — the excluded id is skipped, so the older session resolves
+        assert_eq!(
+            handle.id, older.session_id,
+            "excluded id must be skipped when resolving the latest alias"
+        );
+        fs::remove_dir_all(base).expect("temp dir should clean up");
+    }
+
     #[test]
     fn session_exists_and_delete_are_scoped_to_workspace_store() {
         // given

rust/crates/rusty-claude-cli/src/main.rs

@@ -7886,7 +7886,8 @@ impl LiveCli {
             return Ok(false);
         };
 
-        let (handle, session) = load_session_reference(&session_ref)?;
+        let (handle, session) =
+            load_session_reference_excluding(&session_ref, Some(&self.session.id))?;
         let message_count = session.messages.len();
         let session_id = session.session_id.clone();
         let runtime = build_runtime(
@@ -8582,17 +8583,18 @@ fn latest_managed_session() -> Result<ManagedSessionSummary, Box<dyn std::error:
 
 fn load_session_reference(
     reference: &str,
+) -> Result<(SessionHandle, Session), Box<dyn std::error::Error>> {
+    load_session_reference_excluding(reference, None)
+}
+
+fn load_session_reference_excluding(
+    reference: &str,
+    exclude_id: Option<&str>,
 ) -> Result<(SessionHandle, Session), Box<dyn std::error::Error>> {
     let store = current_session_store()?;
-    // For alias references ("latest", "last", "recent"), allow cross-workspace
-    // resume so /resume latest finds the most recent session globally.
-    // For explicit references, workspace validation is enforced.
-    let result = if runtime::session_control::is_session_reference_alias(reference) {
-        store.load_session_loose(reference)
-    } else {
-        store.load_session(reference)
-    };
-    let loaded = result.map_err(|e| Box::new(e) as Box<dyn std::error::Error>)?;
+    let loaded = store
+        .load_session_excluding(reference, exclude_id)
+        .map_err(|e| Box::new(e) as Box<dyn std::error::Error>)?;
     Ok((
         SessionHandle {
             id: loaded.handle.id,
@@ -17524,16 +17526,26 @@ UU conflicted.rs",
         std::env::set_current_dir(&workspace).expect("switch cwd");
 
         let older = create_managed_session_handle("session-older").expect("older handle");
-        Session::new()
-            .with_persistence_path(older.path.clone())
-            .save_to_path(&older.path)
-            .expect("older session should save");
+        {
+            let mut session = Session::new().with_persistence_path(older.path.clone());
+            session
+                .push_user_text("older session message")
+                .expect("older message should save");
+            session
+                .save_to_path(&older.path)
+                .expect("older session should save");
+        }
         std::thread::sleep(Duration::from_millis(20));
         let newer = create_managed_session_handle("session-newer").expect("newer handle");
-        Session::new()
-            .with_persistence_path(newer.path.clone())
-            .save_to_path(&newer.path)
-            .expect("newer session should save");
+        {
+            let mut session = Session::new().with_persistence_path(newer.path.clone());
+            session
+                .push_user_text("newer session message")
+                .expect("newer message should save");
+            session
+                .save_to_path(&newer.path)
+                .expect("newer session should save");
+        }
 
         let resolved = resolve_session_reference("latest").expect("latest session should resolve");
         assert_eq!(