The log file containing the information referenced will usually be the one named with the hostname on which Tomcat is running. On a simple server (e.g. development environment) this is localhost.<datestamp>.log
With Subversion 1.5 or later the merge is recorded on your local working copy in the svn:mergeinfo property. So this information is not lost.
You can see the merged revisions if you use svn log -g
R. White, and J. Huang. Proceedings of the 33rd International ACM SIGIR Conference on Research and Development in Information Retrieval, page 587--594. New York, NY, USA, ACM, (2010)
A. Paranjape, R. West, L. Zia, and J. Leskovec. Proceedings of the Ninth ACM International Conference on Web Search and Data Mining, page 615--624. ACM, (2016)
M. Atzmueller, and B. Kloepper. Proc. International Conference on Intelligent Data Engineering and Automated Learning, Workshop on Methods for Interpretation of Industrial Event Logs, Heidelberg, Germany, Springer Verlag, ((accepted) 2018)