Remove no longer used references on confirmation dialog disapproval

src/com/fsck/k9/activity/ConfirmationDialog.java

@@ -22,6 +22,26 @@ public class ConfirmationDialog {
     public static Dialog create(final Activity activity, final int dialogId, final int title,
                                 final String message, final int confirmButton, final int cancelButton,
                                 final Runnable action) {
+        return create(activity, dialogId, title, message, confirmButton, cancelButton,
+                action, null);
+    }
+
+    /**
+     * Creates a customized confirmation dialog ({@link AlertDialog}).
+     *
+     * @param activity The activity this dialog is created for.
+     * @param dialogId The id that was used with {@link Activity#showDialog(int)}
+     * @param title The resource id of the text to display in the dialog title
+     * @param message The text to display in the main dialog area
+     * @param confirmButton The resource id of the text to display in the confirm button
+     * @param cancelButton The resource id of the text to display in the cancel button
+     * @param action The action to perform if the user presses the confirm button
+     * @param negativeAction The action to perform if the user presses the cancel button. Can be {@code null}.
+     * @return A confirmation dialog with the supplied arguments
+     */
+    public static Dialog create(final Activity activity, final int dialogId, final int title,
+                                final String message, final int confirmButton, final int cancelButton,
+                                final Runnable action, final Runnable negativeAction) {
 
         final AlertDialog.Builder builder = new AlertDialog.Builder(activity);
         builder.setTitle(title);
@@ -39,6 +59,9 @@ public class ConfirmationDialog {
             @Override
             public void onClick(DialogInterface dialog, int which) {
                 activity.dismissDialog(dialogId);
+                if (negativeAction != null) {
+                    negativeAction.run();
+                }
             }
         });
         return builder.create();
@@ -55,13 +78,13 @@ public class ConfirmationDialog {
      * @param cancelButton The resource id of the text to display in the cancel button
      * @param action The action to perform if the user presses the confirm button
      * @return A confirmation dialog with the supplied arguments
-     * @see #create(Activity,int,int,String,int,int,Runnable)
+     * @see #create(Activity,int,int,String,int,int,Runnable, Runnable)
      */
     public static Dialog create(final Activity activity, final int dialogId, final int title,
                                 final int message, final int confirmButton, final int cancelButton,
                                 final Runnable action) {
 
         return create(activity, dialogId, title, activity.getString(message), confirmButton,
-                      cancelButton, action);
+                      cancelButton, action, null);
     }
 }

src/com/fsck/k9/activity/MessageList.java

@@ -1287,6 +1287,12 @@ public class MessageList
                     // No further need for this reference
                     mActiveMessages = null;
                 }
+            }, new Runnable() {
+                @Override
+                public void run() {
+                    // event for cancel, we don't need this reference any more
+                    mActiveMessages = null;
+                }
             });
         }