aerc: shutdown if socket communication fails

When provided with a mailto argument, aerc tries to connect to an
existing instance via a unix socket. If that fails, it starts up a new
instance and tries again. However, if that fails again (e.g. if the
unix server could not be started) then the new instance will remain open
without any indication that an error occured. Instead, shutdown the new
instance so the user can see the error message.

aerc.go

@@ -123,7 +123,7 @@ func main() {
 			return
 		}
 	}
-	initDone := make(chan struct{})
+	retryExec := false
 	args := os.Args[optind:]
 	if len(args) > 1 {
 		usage()
@@ -134,15 +134,9 @@ func main() {
 		if err == nil {
 			return // other aerc instance takes over
 		}
-		fmt.Fprintf(os.Stderr, "Failed to communicate to aerc: %v", err)
+		fmt.Fprintf(os.Stderr, "Failed to communicate to aerc: %v\n", err)
 		// continue with setting up a new aerc instance and retry after init
-		go func(msg string) {
-			<-initDone
-			err := lib.ConnectAndExec(msg)
-			if err != nil {
-				fmt.Fprintf(os.Stderr, "Failed to communicate to aerc: %v", err)
-			}
-		}(arg)
+		retryExec = true
 	}
 
 	var (
@@ -203,7 +197,16 @@ func main() {
 	// set the aerc version so that we can use it in the template funcs
 	templates.SetVersion(Version)
 
-	close(initDone)
+	if retryExec {
+		// retry execution
+		arg := args[0]
+		err := lib.ConnectAndExec(arg)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to communicate to aerc: %v\n", err)
+			aerc.CloseBackends()
+			return
+		}
+	}
 
 	if isatty.IsTerminal(os.Stderr.Fd()) {
 		setWindowTitle()