From be74fddca241e0b5a791a89725a3a67ea6cd299e Mon Sep 17 00:00:00 2001
From: kevinWangSheng <ltwoggbuty2mh@gmail.com>
Date: Sat, 14 Mar 2026 08:36:29 -0700
Subject: [PATCH] fix(agent): prevent panic from closing events channel while
 readLoop may still send

In 6 agent session implementations (codex, opencode, qoder, iflow, cursor,
gemini), Close() unconditionally calls close(events) after an 8-second
timeout, even when the readLoop goroutine may still be running and
sending events to the channel. Due to Go's select non-determinism, the
readLoop goroutine can choose the send case over the ctx.Done() case,
causing a "send on closed channel" panic.

Move close(events) into the case where wg.Wait() succeeds (readLoop has
fully exited), and skip closing on timeout to prevent the race. This
follows the same safe pattern already used by claudeSession, where the
events channel is only closed after the readLoop goroutine has finished.
---
 agent/codex/session.go    | 2 +-
 agent/cursor/session.go   | 2 +-
 agent/gemini/session.go   | 2 +-
 agent/iflow/session.go    | 2 +-
 agent/opencode/session.go | 2 +-
 agent/qoder/session.go    | 2 +-
 6 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/agent/codex/session.go b/agent/codex/session.go
index 1e7818d..7a903ba 100644
--- a/agent/codex/session.go
+++ b/agent/codex/session.go
@@ -497,10 +497,10 @@ func (cs *codexSession) Close() error {
 	}()
 	select {
 	case <-done:
+		close(cs.events)
 	case <-time.After(8 * time.Second):
 		slog.Warn("codexSession: close timed out, abandoning wg.Wait")
 	}
-	close(cs.events)
 	return nil
 }
 
diff --git a/agent/cursor/session.go b/agent/cursor/session.go
index 041dbad..d163abc 100644
--- a/agent/cursor/session.go
+++ b/agent/cursor/session.go
@@ -464,10 +464,10 @@ func (cs *cursorSession) Close() error {
 	}()
 	select {
 	case <-done:
+		close(cs.events)
 	case <-time.After(8 * time.Second):
 		slog.Warn("cursorSession: close timed out, abandoning wg.Wait")
 	}
-	close(cs.events)
 	return nil
 }
 
diff --git a/agent/gemini/session.go b/agent/gemini/session.go
index d99bccd..718cc7d 100644
--- a/agent/gemini/session.go
+++ b/agent/gemini/session.go
@@ -469,10 +469,10 @@ func (gs *geminiSession) Close() error {
 	}()
 	select {
 	case <-done:
+		close(gs.events)
 	case <-time.After(8 * time.Second):
 		slog.Warn("geminiSession: close timed out, abandoning wg.Wait")
 	}
-	close(gs.events)
 	return nil
 }
 
diff --git a/agent/iflow/session.go b/agent/iflow/session.go
index 2488211..1d0cf96 100644
--- a/agent/iflow/session.go
+++ b/agent/iflow/session.go
@@ -897,9 +897,9 @@ func (s *iflowSession) Close() error {
 	}()
 	select {
 	case <-done:
+		close(s.events)
 	case <-time.After(8 * time.Second):
 		slog.Warn("iflowSession: close timed out, abandoning wg.Wait")
 	}
-	close(s.events)
 	return nil
 }
diff --git a/agent/opencode/session.go b/agent/opencode/session.go
index 3ee4b4f..ebe3a4e 100644
--- a/agent/opencode/session.go
+++ b/agent/opencode/session.go
@@ -393,10 +393,10 @@ func (s *opencodeSession) Close() error {
 	}()
 	select {
 	case <-done:
+		close(s.events)
 	case <-time.After(8 * time.Second):
 		slog.Warn("opencodeSession: close timed out, abandoning wg.Wait")
 	}
-	close(s.events)
 	return nil
 }
 
diff --git a/agent/qoder/session.go b/agent/qoder/session.go
index e4492e9..c98ca63 100644
--- a/agent/qoder/session.go
+++ b/agent/qoder/session.go
@@ -288,10 +288,10 @@ func (qs *qoderSession) Close() error {
 	}()
 	select {
 	case <-done:
+		close(qs.events)
 	case <-time.After(8 * time.Second):
 		slog.Warn("qoderSession: close timed out, abandoning wg.Wait")
 	}
-	close(qs.events)
 	return nil
 }