How can KDiff3 be used properly with TortoiseSVN to resolve conflicts?

Mine is a bit longer:

"C:\Program Files\KDiff3\kdiff3.exe" %base %mine %theirs -o %merged --L1 Base --L2 Mine --L3 Theirs

In case there's someone else like me, let me point out his is done in TortoiseSVN->Settings->Diff Viewer. I installed KDiff3 in Windows with Tortoise already installed and it got configured automatically. It took me some time to figure out where this needed to be done.

Turns out I just needed a more specific command line. I had it set simply to the path to kdiff3.exe, and hoped the default arguments passed from TortoiseSVN would be enough. Not so. Here's the one needed (the key being the -o argument):

C:\Program Files\KDiff3\kdiff3.exe %base %theirs %mine -o %merged