[SCIM-33] fixes NPE while updating groups with delta and PATCH is gro…

…up update method (#100)

src/main/java/net/tirasa/connid/bundles/scim/common/AbstractSCIMConnector.java

@@ -582,13 +582,20 @@ public Set<AttributeDelta> updateDelta(
                 // only values to add and remove are supported
                 modifications.stream().
                         filter(ad -> SCIMAttributeUtils.SCIM_USER_GROUPS.equalsIgnoreCase(ad.getName())).
-                        findFirst().ifPresent(grpsAd -> fillGroupPatches(
+                        findFirst().ifPresent(grmod -> fillGroupPatches(
                         currentUser,
                         groupPatches,
-                        CollectionUtil.isEmpty(grpsAd.getValuesToAdd())
-                        ? grpsAd.getValuesToReplace().stream().map(String.class::cast).collect(Collectors.toList())
-                        : grpsAd.getValuesToAdd().stream().map(String.class::cast).collect(Collectors.toList()),
-                        grpsAd.getValuesToRemove().stream().map(String.class::cast).collect(Collectors.toList())));
+                        CollectionUtil.isEmpty(grmod.getValuesToAdd())
+                        ? CollectionUtil.isEmpty(grmod.getValuesToReplace())
+                        ? Collections.emptyList()
+                        : grmod.getValuesToReplace().stream().map(String.class::cast)
+                                .collect(Collectors.toList())
+                        : CollectionUtil.isEmpty(grmod.getValuesToAdd())
+                        ? Collections.emptyList()
+                        : grmod.getValuesToAdd().stream().map(String.class::cast).collect(Collectors.toList()),
+                        CollectionUtil.isEmpty(grmod.getValuesToRemove())
+                        ? Collections.emptyList()
+                        : grmod.getValuesToRemove().stream().map(String.class::cast).collect(Collectors.toList())));
             } else {
                 LOG.warn("Group update method must be set to PATCH while updating through UPDATE_DELTA");
             }

src/main/java/net/tirasa/connid/bundles/scim/common/service/AbstractSCIMService.java

@@ -349,7 +349,7 @@ protected void checkServiceErrors(final Response response) {
         }
 
         if (response.getStatusInfo().getFamily() != Status.Family.SUCCESSFUL) {
-            SCIMUtils.handleGeneralError("While executing SCIM request");
+            SCIMUtils.handleGeneralError("While executing SCIM request " + response.getStatus());
         }
     }