Compare with another branch shows files with no difference [SVN 1.7 or older] (bug 326694)

https://bugs.eclipse.org/bugs/show_bug.cgi?id=326694

git-svn-id: https://dev.eclipse.org/svnroot/technology/org.eclipse.subversive/trunk@21520 ee007c2a-0a25-0410-9ab9-bf268980928c