--- src/svn.cpp.orig	2018-05-27 18:34:59 UTC
+++ src/svn.cpp
@@ -873,7 +873,13 @@ int SvnRevision::exportInternal(const ch
     // changes across directory re-organizations and wholesale branch
     // imports.
     //
-    if (path_from != NULL && preveffectiverepository == effectiveRepository && prevbranch != branch) {
+    // NOTE(uqs): HACK ALERT! Only merge between head, projects, and user
+    // branches for the FreeBSD repositories. Never merge into stable or
+    // releng, as we only ever cherry-pick changes to those branches.
+    // FIXME: Needs to move into the ruleset ...
+    if (path_from != NULL && preveffectiverepository == effectiveRepository && prevbranch != branch &&
+            (branch.startsWith("master") || branch.startsWith("head") ||
+             branch.startsWith("projects") || branch.startsWith("user"))) {
         if(ruledebug)
             qDebug() << "copy from branch" << prevbranch << "to branch" << branch << "@rev" << rev_from;
         txn->noteCopyFromBranch (prevbranch, rev_from);