SVN Merge returns nothing

Here is the scenario: Windows Vista environment. SVN version 1.6.11.

I'm on my branch directory. I want to update my branch with a particular change from my trunk. Using command line (using SlikSVN) I enter the following and it returns nothing (returns a blank line and no merge occurs):

svn merge -r 11846:11891 http://trunk//AppConstants.java

When I do the equivalent using Tortoise SVN, it says "Completed" but nothing gets merged either. When I do a svn diff I clearly see the differences I want to merge in from the trunk to my branch. The diff command I am using is svn diff -r 11846:11891 http://开发者_Go百科trunk//AppConstants.java.

Can anyone figure why no merge occurs? Thanks!!!