Bump dependency github.com/godbus/dbus@v19 (2ff6f7ffd60f)

vendor/github.com/godbus/dbus/conn_other.go

@@ -6,12 +6,14 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"os/exec"
+	"os/user"
+	"path"
+	"strings"
 )
 
-const defaultSystemBusAddress = "unix:path=/var/run/dbus/system_bus_socket"
-
 func getSessionBusPlatformAddress() (string, error) {
 	cmd := exec.Command("dbus-launch")
 	b, err := cmd.CombinedOutput()
@@ -33,10 +35,57 @@ func getSessionBusPlatformAddress() (string, error) {
 	return addr, nil
 }
 
-func getSystemBusPlatformAddress() string {
-	address := os.Getenv("DBUS_SYSTEM_BUS_ADDRESS")
-	if address != "" {
-		return fmt.Sprintf("unix:path=%s", address)
+// tryDiscoverDbusSessionBusAddress tries to discover an existing dbus session
+// and return the value of its DBUS_SESSION_BUS_ADDRESS.
+// It tries different techniques employed by different operating systems,
+// returning the first valid address it finds, or an empty string.
+//
+// * /run/user/<uid>/bus           if this exists, it *is* the bus socket. present on
+//                                 Ubuntu 18.04
+// * /run/user/<uid>/dbus-session: if this exists, it can be parsed for the bus
+//                                 address. present on Ubuntu 16.04
+//
+// See https://dbus.freedesktop.org/doc/dbus-launch.1.html
+func tryDiscoverDbusSessionBusAddress() string {
+	if runtimeDirectory, err := getRuntimeDirectory(); err == nil {
+
+		if runUserBusFile := path.Join(runtimeDirectory, "bus"); fileExists(runUserBusFile) {
+			// if /run/user/<uid>/bus exists, that file itself
+			// *is* the unix socket, so return its path
+			return fmt.Sprintf("unix:path=%s", runUserBusFile)
+		}
+		if runUserSessionDbusFile := path.Join(runtimeDirectory, "dbus-session"); fileExists(runUserSessionDbusFile) {
+			// if /run/user/<uid>/dbus-session exists, it's a
+			// text file // containing the address of the socket, e.g.:
+			// DBUS_SESSION_BUS_ADDRESS=unix:abstract=/tmp/dbus-E1c73yNqrG
+
+			if f, err := ioutil.ReadFile(runUserSessionDbusFile); err == nil {
+				fileContent := string(f)
+
+				prefix := "DBUS_SESSION_BUS_ADDRESS="
+
+				if strings.HasPrefix(fileContent, prefix) {
+					address := strings.TrimRight(strings.TrimPrefix(fileContent, prefix), "\n\r")
+					return address
+				}
+			}
+		}
+	}
+	return ""
+}
+
+func getRuntimeDirectory() (string, error) {
+	if currentUser, err := user.Current(); err != nil {
+		return "", err
+	} else {
+		return fmt.Sprintf("/run/user/%s", currentUser.Uid), nil
+	}
+}
+
+func fileExists(filename string) bool {
+	if _, err := os.Stat(filename); !os.IsNotExist(err) {
+		return true
+	} else {
+		return false
 	}
-	return defaultSystemBusAddress
 }