Bug 4100: Parts of settings that have been changed to not contain any

setting anymore are now removed from the settings tree instead of
setting an empty object. In addition if the whole settings object is
empty, the settings entry is now removed instead of saving empty
settings to the storage.

java/com.sap.sse.gwt/src/com/sap/sse/gwt/client/shared/settings/StorableSettingsRepresentation.java

@@ -56,7 +56,7 @@ public class StorableSettingsRepresentation {
         if(internalSettingsRepresentation != null) {
             return internalSettingsRepresentation.toString();
         } else {
-            return "{}";
+            return null;
         }
     }
     
@@ -76,8 +76,17 @@ public class StorableSettingsRepresentation {
      */
     public static StorableSettingsRepresentation patchSettingsRepresentation(StorableSettingsRepresentation root,
             Iterable<String> path, StorableSettingsRepresentation newSettings) {
+        JSONObject settingsAsJson;
+        if(newSettings == null) {
+            settingsAsJson = null;
+        } else {
+            settingsAsJson = newSettings.asJson();
+            if(settingsAsJson != null && settingsAsJson.keySet().isEmpty()) {
+                settingsAsJson = null;
+            }
+        }
         JSONObject patchedSettingsJsonRepresentation = patchJsonObject(root == null ? null : root.asJson(),
-                path.iterator(), newSettings == null ? null : newSettings.asJson());
+                path.iterator(), settingsAsJson);
         return new StorableSettingsRepresentation(patchedSettingsJsonRepresentation);
     }
     
@@ -92,8 +101,8 @@ public class StorableSettingsRepresentation {
      * @param pipelineLevel
      * @return
      */
-    private static JSONObject patchJsonObject(JSONObject root, Iterator<String> path,
-            JSONObject newSettings) {
+    private static JSONObject patchJsonObject(JSONObject root, final Iterator<String> path,
+            final JSONObject newSettings) {
         if (!path.hasNext()) {
             return newSettings;
         }
@@ -103,23 +112,27 @@ public class StorableSettingsRepresentation {
         String current = path.next();
         // we need to go further
         if (path.hasNext()) {
-            JSONValue child = root.get(current);
             boolean haskey = root.containsKey(current);
-            if (child == null || child.isObject() == null) {
-                if (haskey) {
-                    GWT.log("Warning: replacing some subtree element that is wrong type!");
+            if(haskey || newSettings != null) {
+                // if (!haskey && newSettings == null) we have currently no settings on the path and there are no new settings,
+                // so do not have to do anything
+                JSONObject currentObject = null;
+                JSONValue child = root.get(current);
+                if (child != null) {
+                    currentObject = child.isObject();
+                    if (currentObject == null) {
+                        GWT.log("Warning: replacing some subtree element that is wrong type!");
+                    }
                 }
-                if(newSettings == null){
-                    //no need to create tree, if we only want to remove settings!
-                    return null;
-                }
-                child = new JSONObject();
-                root.put(current, child);
+                root.put(current, patchJsonObject(child.isObject(), path, newSettings));
             }
-            return patchJsonObject(child.isObject(), path, newSettings);
         } else {
             root.put(current, newSettings);
         }
+        if(root.keySet().isEmpty()) {
+            // If there aren't any settings in this path, we just remove the whole path
+            root = null;
+        }
         return root;
     }
     

java/com.sap.sse.security.ui/src/main/java/com/sap/sse/security/ui/settings/UserSettingsStorageManager.java

@@ -95,13 +95,19 @@ public class UserSettingsStorageManager implements SettingsStorageManager {
         if (localStorage != null) {
             if (settingsRepresentations.hasStoredUserSettings()) {
                 localStorage.removeItem(storageKeyForUserSettings);
-                localStorage.setItem(storageKeyForUserSettings,
-                        settingsRepresentations.getUserSettingsRepresentation().asString());
+                final String settingsString = settingsRepresentations.getUserSettingsRepresentation().asString();
+                if(settingsString != null) {
+                    localStorage.setItem(storageKeyForUserSettings,
+                            settingsString);
+                }
             }
             if (settingsRepresentations.hasStoredDocumentSettings()) {
                 localStorage.removeItem(storageKeyForDocumentSettings);
-                localStorage.setItem(storageKeyForDocumentSettings,
-                        settingsRepresentations.getDocumentSettingsRepresentation().asString());
+                final String settingsString = settingsRepresentations.getDocumentSettingsRepresentation().asString();
+                if(settingsString != null) {
+                    localStorage.setItem(storageKeyForDocumentSettings,
+                            settingsString);
+                }
             }
         }
     }