Merge branch 'master' into 0.52.x

# Conflicts:
#	CHANGELOG.md
#	build.gradle

Author: ajungg

CHANGELOG.md

@@ -12,6 +12,11 @@ All notable changes to this project will be documented in this file.
 - Added optional CheckInManager and CheckInLocationManager which can used for geofencing store locations
 - Added support for PayOne credit card tokenization and transactions
 
+## [0.51.6]
+
+### Fixed
+- Only fallback to offline payment method if an offline capable payment method is selected
+
 ## [0.51.5]
 
 ### Fixed

core/src/main/java/io/snabble/sdk/Checkout.java

@@ -255,7 +255,7 @@ private PaymentMethod getFallbackPaymentMethod() {
     }
 
     public void checkout() {
-        checkout(-1);
+        checkout(-1, false);
     }
 
     /**
@@ -268,7 +268,7 @@ public void checkout() {
      * You then need to sometime after call @link Checkout#pay(PaymentMethod)}
      * to pay with that payment method.
      */
-    public void checkout(long timeout) {
+    public void checkout(long timeout, boolean allowFallbackAfterTimeout) {
         checkoutProcess = null;
         rawCheckoutProcess = null;
         signedCheckoutInfo = null;
@@ -349,7 +349,7 @@ public void unknownError() {
             @Override
             public void connectionError() {
                 PaymentMethod fallback = getFallbackPaymentMethod();
-                if(fallback != null) {
+                if(fallback != null && allowFallbackAfterTimeout) {
                     paymentMethod = fallback;
                     priceToPay = shoppingCart.getTotalPrice();
                     checkoutRetryer.add(backendCart);

ui/src/main/java/io/snabble/sdk/ui/cart/CheckoutBar.kt

@@ -217,7 +217,7 @@ open class CheckoutBar @JvmOverloads constructor(
                             object : OneShotClickListener() {
                                 override fun click() {
                                     if (entry.paymentMethod.isOfflineMethod) {
-                                        project.checkout.checkout(3000)
+                                        project.checkout.checkout(3000, true)
                                     } else {
                                         project.checkout.checkout()
                                     }