From 072b5f453ccb8c3d79f55be80f5db9e71cf17a31 Mon Sep 17 00:00:00 2001
From: Reto Brunner <reto@labrat.space>
Date: Wed, 7 Aug 2019 08:21:15 +0200
Subject: [PATCH] Close backends prior to shutdown

We need some way to signal the backends that we are about to shutdown,
allowing them to clean up (for example in notmuch committing the db changes).
This commit implements a hook which gets called upon shutdown, providing
backends implement the io.Closer interface.
---
 aerc.go         |  1 +
 widgets/aerc.go | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/aerc.go b/aerc.go
index c71c384..c5d93ac 100644
--- a/aerc.go
+++ b/aerc.go
@@ -178,4 +178,5 @@ func main() {
 			time.Sleep(16 * time.Millisecond)
 		}
 	}
+	aerc.CloseBackends()
 }
diff --git a/widgets/aerc.go b/widgets/aerc.go
index 23dac3e..5a7914a 100644
--- a/widgets/aerc.go
+++ b/widgets/aerc.go
@@ -2,6 +2,7 @@ package widgets
 
 import (
 	"errors"
+	"io"
 	"log"
 	"net/url"
 	"strings"
@@ -405,3 +406,21 @@ func (aerc *Aerc) Mailto(addr *url.URL) error {
 	})
 	return nil
 }
+
+func (aerc *Aerc) CloseBackends() error {
+	var returnErr error
+	for _, acct := range aerc.accounts {
+		var raw interface{} = acct.worker.Backend
+		c, ok := raw.(io.Closer)
+		if !ok {
+			continue
+		}
+		err := c.Close()
+		if err != nil {
+			returnErr = err
+			aerc.logger.Printf("Closing backend failed for %v: %v\n",
+				acct.Name(), err)
+		}
+	}
+	return returnErr
+}