From 9d0d090fc1d683accc8bd1b354425c23cbe9fb6a Mon Sep 17 00:00:00 2001
From: Simon Ruderich <simon@ruderich.org>
Date: Tue, 18 May 2021 10:50:43 +0200
Subject: [PATCH] safcm: don't hang on error before a connection is established

---
 cmd/safcm/main_sync_test.go | 14 ++++++++++++++
 cmd/safcm/sync.go           |  1 +
 rpc/conn.go                 |  7 ++++++-
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/cmd/safcm/main_sync_test.go b/cmd/safcm/main_sync_test.go
index 16aad16..fdbe98f 100644
--- a/cmd/safcm/main_sync_test.go
+++ b/cmd/safcm/main_sync_test.go
@@ -348,6 +348,20 @@ executed 2 command(s):
 	logRegexp := regexp.MustCompile(`^\d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2} `)
 	detectedRegexp := regexp.MustCompile(`detected_\S+`)
 
+	t.Run("error before connection is established", func(t *testing.T) {
+		// Fake $PATH so safcm cannot find the `ssh` binary.
+		path := os.Getenv("PATH")
+		os.Setenv("PATH", "")
+		defer os.Setenv("PATH", path)
+
+		cmd := exec.Command("../../../../../safcm",
+			"sync", "-n", "no-settings.example.org")
+		_, err := cmd.CombinedOutput()
+		if err == nil {
+			t.Errorf("err = nil")
+		}
+	})
+
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
 			if tc.remove {
diff --git a/cmd/safcm/sync.go b/cmd/safcm/sync.go
index 6fe65fa..1a482b3 100644
--- a/cmd/safcm/sync.go
+++ b/cmd/safcm/sync.go
@@ -380,6 +380,7 @@ func (s *Sync) Host(wg *sync.WaitGroup) error {
 		SshConfig: s.config.SshConfig,
 	})
 	if err != nil {
+		conn.Kill()
 		return err
 	}
 	defer conn.Kill()
diff --git a/rpc/conn.go b/rpc/conn.go
index 9786941..03b7485 100644
--- a/rpc/conn.go
+++ b/rpc/conn.go
@@ -124,9 +124,14 @@ func (c *Conn) wait() error {
 }
 
 // Kill forcefully terminates the connection. It's safe to call Kill (and
-// Wait) multiple times.
+// Wait) multiple times. Calling it before Dial*() was called will only close
+// the Events channel.
 func (c *Conn) Kill() error {
 	if c.cmd == nil {
+		if c.events != nil {
+			close(c.events)
+			c.events = nil
+		}
 		return fmt.Errorf("Dial*() not called or already terminated")
 	}
 
-- 
2.43.2