SVN merge between branches is actually overwrite?

I just found if I merge branch B to branch A, the two branches will become the same. changes in branch A will gone. Is this by design? or I did something wrong? I am using the latest Tortoise.

I did more than once with the instruction found online:

In the From URL option, you should mention the branch to which you have to merge. For example, assume that there are 2 branches branch A and branch B, and you want to merge branch B to branch A. In TortoiseSVN, click on Merge option and then select Merge two different trees option. In the From URL, please mention URL of branch A and in the To URL, mention URL of branch B. This should merge branch B to branch A without loosing any files.

Thanks,James
Received on 2016-11-26 14:49:19 CET