Break current device ID retrieval out into exported function GetCurrentDeviceID(); fix duplicate device IDs being generated by not deleting the old one before a potentially failed registration

core/init.go

@@ -60,13 +60,7 @@ func DirInit(preserveOldConfigDir bool) string {
 	}
 
 	// get old device ID before its potential removal
-	oldDeviceIDList := GenDeviceIDList(false) // errorOnFail is false so that nil is received when the devices directory does not exist
+	oldDeviceID := GetCurrentDeviceID()
-	var oldDeviceID string
-	if oldDeviceIDList != nil && len(*oldDeviceIDList) > 0 { // ensure not derferencing nil, which occurs when the devices directory does not exist
-		oldDeviceID = (*oldDeviceIDList)[0].Name()
-	} else {
-		oldDeviceID = FSMisc // indicates to server that no device ID is being replaced
-	}
 
 	// remove existing config directory (if it exists and not in append mode)
 	if !preserveOldConfigDir {
@@ -87,3 +81,16 @@ func DirInit(preserveOldConfigDir bool) string {
 
 	return oldDeviceID
 }
+
+// GetOldDeviceID returns the current device ID or
+// FSMisc if there is no device ID (e.g. first run).
+func GetCurrentDeviceID() string {
+	deviceIDList := GenDeviceIDList(false) // errorOnFail is false so that nil is received when the devices directory does not exist
+	var deviceID string
+	if deviceIDList != nil && len(*deviceIDList) > 0 { // ensure not derferencing nil, which occurs when the devices directory does not exist
+		deviceID = (*deviceIDList)[0].Name()
+	} else {
+		deviceID = FSMisc // indicates to server that no device ID is being replaced
+	}
+	return deviceID
+}

sync/init.go

@@ -27,6 +27,12 @@ func DeviceIDGen(oldDeviceID string) (string, string) {
 	}
 	_ = fileToClose.Close() // error ignored; if the file could be created, it can probably be closed
 
+	// remove old device ID file (locally; may not exist)
+	err = os.RemoveAll(core.ConfigDir + core.PathSeparator + "devices" + core.PathSeparator + oldDeviceID)
+	if err != nil {
+		core.PrintError("Failed to remove old device ID file (locally): "+err.Error(), core.ErrorWrite, true)
+	}
+
 	// register new device ID with server and fetch remote EntryRoot and OS type
 	// also removes the old device ID file (remotely)
 	// manualSync is true so the user is alerted if device ID registration fails
@@ -37,11 +43,5 @@ func DeviceIDGen(oldDeviceID string) (string, string) {
 		core.PrintError("Init failed - Unable to close SSH client: "+err.Error(), core.ErrorServerConnection, true)
 	}
 
-	// remove old device ID file (locally; may not exist)
-	err = os.RemoveAll(core.ConfigDir + core.PathSeparator + "devices" + core.PathSeparator + oldDeviceID)
-	if err != nil {
-		core.PrintError("Failed to remove old device ID file (locally): "+err.Error(), core.ErrorWrite, true)
-	}
-
 	return sshEntryRootSSHIsWindows[0], sshEntryRootSSHIsWindows[1]
 }