How can I pre-delay svn merge conflicts?

I often run into conflicts when performing a Subversion merge, for example:

svn merge -r10347:HEAD ^/branches/header-and-navbar 

I know about --dry-run, and I do this to get a preview.

But then, after executing it for real, if I want to select “delay” for each conflict, it can take a long time for a large number of files.

How can I tell Subversion ahead of time so as not to ask me about each file?