Fix bug, that preferences where not stored

Author: adangel

net.sourceforge.pmd.eclipse.plugin/src/main/java/net/sourceforge/pmd/eclipse/ui/priority/PriorityDescriptorCache.java

@@ -42,6 +42,9 @@ public void dumpTo(PrintStream out) {
     public void loadFromPreferences() {
         IPreferences preferences = preferencesManager().loadPreferences();
         for (RulePriority rp : UISettings.currentPriorities(true)) {
+            // note: the priority descriptors are cloned here, so that any changes to them
+            // does not automatically get stored. Changes might occur while configuring the
+            // preferences, but the user might cancel.
             uiDescriptorsByPriority.put(rp, preferences.getPriorityDescriptor(rp).clone());
         }
         refreshImages();
@@ -54,7 +57,7 @@ public void storeInPreferences() {
         for (Map.Entry<RulePriority, PriorityDescriptor> entry : uiDescriptorsByPriority.entrySet()) {
             prefs.setPriorityDescriptor(entry.getKey(), entry.getValue());
         }
-        mgr.storePreferences(prefs);
+        prefs.sync();
         // recreate images with the changed settings
         refreshImages();
     }
@@ -64,11 +67,11 @@ public PriorityDescriptor descriptorFor(RulePriority priority) {
     }
 
     public boolean hasChanges() {
-        IPreferences preferences = preferencesManager().reloadPreferences();
+        IPreferences currentPreferences = preferencesManager().loadPreferences();
 
         for (RulePriority rp : UISettings.currentPriorities(true)) {
             PriorityDescriptor newOne = uiDescriptorsByPriority.get(rp);
-            PriorityDescriptor currentOne = preferences.getPriorityDescriptor(rp);
+            PriorityDescriptor currentOne = currentPreferences.getPriorityDescriptor(rp);
             if (newOne.equals(currentOne)) {
                 continue;
             }