http://www.sublimerge.com/docs/vcs-integration.html#subversion-svn

(I am not the author of sublimerge plugin)

There is an issue cannot be solved by the plugin:

ST3: running Sublimerge from command line (only when Sublime Text was not already running) only opens files without doing diff. Otherwise, when launching Sublimerge while ST is running, everything works fine.This is caused by asynchronous plugins loader in ST3 and cannot be fixed from plugin level.

Cound you add some mechanism to allow passing data to plugin when the plugin is loaded?

For example, add an argement called

--plugin-command { "dependency": [ "plugin-name" ], "data": { ... } }

Thank you.