OK I’ve find the answer by myself.
TortoiseSVN – Creating and Applying Patches
A short summary of the mentioned page:
For open source projects (like WordPress) everyone has read access to the repository, and anyone can make a contribution to the project. So how are those contributions controlled? If just anyone could commit changes, the project would be permanently unstable and probably permanently broken. In this situation the change is managed by submitting a patch file to the development team, who do have write access. They can review the patch first, and then either submit it to the repository or reject it back to the author.
Patch files are simply Unified-Diff files showing the differences between your working copy and the base revision.
Creating a Patch File
Creating a patch is meaning to make some changes to your copies of the files that need a fix, and than export all the changes you’ve made to a *.patch file.
You can select the files you want included in the patch, just as you would with a full commit. This will produce a single file containing a summary of all the changes you have made to the selected files since the last update from the repository. So you can produce separate patches containing changes to different sets of files. Of course, if you create a patch file, make some more changes to the same files and then create another patch, the second patch file will include both sets of changes.
Applying a Patch File
Patch files are applied only to your working copy and not on the SVN.
This should be done from the same folder level as was used to create the patch. If you are not sure what this is, just look at the first line of the patch file. For example, if the first file being worked on was doc/source/english/chapter1.xml and the first line in the patch file is Index: english/chapter1.xml then you need to apply the patch to the doc/source/ folder.
Once you have selected the patch file and working copy location, TortoiseMerge runs to merge the changes from the patch file with your working copy. A small window lists the files which have been changed. Double click on each one in turn, review the changes and save the merged files.
