From 2882b91e7c6bde73a0fc60b167dae4ccda602c1d Mon Sep 17 00:00:00 2001
From: dj-oyu <68707227+dj-oyu@users.noreply.github.com>
Date: Sun, 15 Mar 2026 17:14:04 +0900
Subject: [PATCH] fix: heartbeat worktree uses stale plan dir and blocks
 workspace reads

Heartbeat created worktrees against GetPlanWorkDir() which could return
a stale path from a previous plan (e.g. a different repository), causing
gh commands to target the wrong repo. Now always uses agent.Workspace.

Also fix resolveFS to allow reading absolute paths under the original
workspace when operating inside a worktree, preventing "path escapes
workspace" errors for files like HEARTBEAT.md.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 pkg/agent/loop.go          |  5 +++--
 pkg/tools/workspace_ctx.go | 10 ++++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/pkg/agent/loop.go b/pkg/agent/loop.go
index 025c03173..b3e92144e 100644
--- a/pkg/agent/loop.go
+++ b/pkg/agent/loop.go
@@ -2511,10 +2511,11 @@ func (al *AgentLoop) executeToolCalls(
 			})
 
 		// Heartbeat lazy worktree: create worktree on first write-tool call
+		// Always use ai.Workspace (not GetPlanWorkDir) to avoid creating worktrees
+		// against stale project paths from previous plans.
 		if opts.Background && isWriteTool(tc.Name) && !agent.IsInWorktree(opts.SessionKey) {
 			taskName := "heartbeat-" + time.Now().Format("20060102")
-			hbDir := agent.ContextBuilder.GetPlanWorkDir()
-			if wt, wtErr := agent.ActivateWorktree(opts.SessionKey, taskName, hbDir); wtErr == nil {
+			if wt, wtErr := agent.ActivateWorktree(opts.SessionKey, taskName, agent.Workspace); wtErr == nil {
 				logger.InfoCF("agent", "Heartbeat worktree created", map[string]any{"branch": wt.Branch})
 			}
 		}
diff --git a/pkg/tools/workspace_ctx.go b/pkg/tools/workspace_ctx.go
index 9460431a9..b8657647f 100644
--- a/pkg/tools/workspace_ctx.go
+++ b/pkg/tools/workspace_ctx.go
@@ -61,6 +61,16 @@ func resolveFS(ctx context.Context, fs fileSystem, path string) fileSystem {
 		return fs
 	}
 
+	// Absolute paths under the original workspace use original fs
+	// (e.g. heartbeat reading workspace files while in a worktree)
+	if filepath.IsAbs(path) {
+		if sfs, ok := fs.(*sandboxFs); ok {
+			if strings.HasPrefix(path, sfs.workspace+"/") || path == sfs.workspace {
+				return fs
+			}
+		}
+	}
+
 	// Only sandboxFs supports workspace override
 
 	if sfs, ok := fs.(*sandboxFs); ok {