Index: /trunk/src/org/openstreetmap/josm/actions/ToggleAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/actions/ToggleAction.java	(revision 16823)
+++ /trunk/src/org/openstreetmap/josm/actions/ToggleAction.java	(revision 16824)
@@ -101,5 +101,5 @@
      */
     public final void removeButtonModel(ButtonModel model) {
-        if (model != null && buttonModels.contains(model)) {
+        if (model != null) {
             buttonModels.remove(model);
         }
Index: /trunk/src/org/openstreetmap/josm/actions/UploadAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/actions/UploadAction.java	(revision 16823)
+++ /trunk/src/org/openstreetmap/josm/actions/UploadAction.java	(revision 16824)
@@ -129,10 +129,6 @@
     public static void unregisterUploadHook(UploadHook hook) {
         if (hook == null) return;
-        if (UPLOAD_HOOKS.contains(hook)) {
-            UPLOAD_HOOKS.remove(hook);
-        }
-        if (LATE_UPLOAD_HOOKS.contains(hook)) {
-            LATE_UPLOAD_HOOKS.remove(hook);
-        }
+        UPLOAD_HOOKS.remove(hook);
+        LATE_UPLOAD_HOOKS.remove(hook);
     }
 
Index: /trunk/src/org/openstreetmap/josm/data/osm/DefaultNameFormatter.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/osm/DefaultNameFormatter.java	(revision 16823)
+++ /trunk/src/org/openstreetmap/josm/data/osm/DefaultNameFormatter.java	(revision 16824)
@@ -81,7 +81,5 @@
     public static void unregisterFormatHook(NameFormatterHook hook) {
         if (hook == null) return;
-        if (formatHooks.contains(hook)) {
-            formatHooks.remove(hook);
-        }
+        formatHooks.remove(hook);
     }
 
Index: /trunk/src/org/openstreetmap/josm/data/validation/tests/Addresses.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/validation/tests/Addresses.java	(revision 16823)
+++ /trunk/src/org/openstreetmap/josm/data/validation/tests/Addresses.java	(revision 16824)
@@ -161,5 +161,5 @@
                             if (!ignoredAddresses.contains(simplifiedAddress)) {
                                 ignoredAddresses.add(simplifiedAddress);
-                            } else if (knownAddresses.containsKey(simplifiedAddress)) {
+                            } else {
                                 knownAddresses.remove(simplifiedAddress);
                             }
Index: /trunk/src/org/openstreetmap/josm/gui/conflict/pair/AbstractListMergeModel.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/conflict/pair/AbstractListMergeModel.java	(revision 16823)
+++ /trunk/src/org/openstreetmap/josm/gui/conflict/pair/AbstractListMergeModel.java	(revision 16824)
@@ -223,5 +223,5 @@
     public void addPropertyChangeListener(PropertyChangeListener listener) {
         synchronized (listeners) {
-            if (listener != null && !listeners.contains(listener)) {
+            if (listener != null) {
                 listeners.add(listener);
             }
@@ -231,5 +231,5 @@
     public void removePropertyChangeListener(PropertyChangeListener listener) {
         synchronized (listeners) {
-            if (listener != null && listeners.contains(listener)) {
+            if (listener != null) {
                 listeners.remove(listener);
             }
Index: /trunk/src/org/openstreetmap/josm/gui/util/CellEditorSupport.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/util/CellEditorSupport.java	(revision 16823)
+++ /trunk/src/org/openstreetmap/josm/gui/util/CellEditorSupport.java	(revision 16824)
@@ -41,5 +41,5 @@
     public final void addCellEditorListener(CellEditorListener l) {
         synchronized (this) {
-            if (l != null && !listeners.contains(l)) {
+            if (l != null) {
                 listeners.add(l);
             }
@@ -53,5 +53,5 @@
     public final void removeCellEditorListener(CellEditorListener l) {
         synchronized (this) {
-            if (l != null && listeners.contains(l)) {
+            if (l != null) {
                 listeners.remove(l);
             }
Index: /trunk/src/org/openstreetmap/josm/plugins/ReadLocalPluginInformationTask.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/plugins/ReadLocalPluginInformationTask.java	(revision 16823)
+++ /trunk/src/org/openstreetmap/josm/plugins/ReadLocalPluginInformationTask.java	(revision 16824)
@@ -184,7 +184,5 @@
         for (PluginHandler.DeprecatedPlugin p : PluginHandler.DEPRECATED_PLUGINS) {
             if (canceled) return;
-            if (availablePlugins.containsKey(p.name)) {
-                availablePlugins.remove(p.name);
-            }
+            availablePlugins.remove(p.name);
         }
     }
Index: /trunk/test/unit/org/openstreetmap/josm/gui/preferences/imagery/ImageryPreferenceTestIT.java
===================================================================
--- /trunk/test/unit/org/openstreetmap/josm/gui/preferences/imagery/ImageryPreferenceTestIT.java	(revision 16823)
+++ /trunk/test/unit/org/openstreetmap/josm/gui/preferences/imagery/ImageryPreferenceTestIT.java	(revision 16824)
@@ -130,6 +130,5 @@
     private boolean addError(ImageryInfo info, String error) {
         String errorMsg = error.replace('\n', ' ');
-        if (notIgnoredErrors.contains(errorMsg))
-            notIgnoredErrors.remove(errorMsg);
+        notIgnoredErrors.remove(errorMsg);
         return addError(isIgnoredError(errorMsg) ? ignoredErrors : errors, info, errorMsg);
     }