I'm too long out of the game to offer meaningful review and testing on this, but I definitely appreciate the thorough write-up. And given the comments I left sprinkled in that source file (so many years ago...) about how inefficient some of the filtering was when the master/slave repository paths were identical, chances are pretty good that I did most of my testing in exactly that configuration.
-- Mike On Wed, Jan 14, 2026 at 7:18 AM Jordan Peck via dev < [email protected]> wrote: > Hi, > > I've identified and fixed a bug in mod_dav_svn's master/slave proxy > functionality (SVNMasterURI) that causes COPY and MOVE operations to > fail with a 400 error when the slave and master repositories are > hosted at different paths. > > > STEPS TO REPRODUCE > ================== > > 1. Configure a master SVN server with the repository at /repo: > > # Master server (master-server.example.com) > <Location /repo> > DAV svn > SVNPath /var/svn/myrepo > </Location> > > 2. Configure a slave SVN server with the repository at a different > path (/svn/repo) and SVNMasterURI pointing to the master: > > # Slave server (slave-server.example.com) > <Location /svn/repo> > DAV svn > SVNPath /var/svn/myrepo-slave > SVNMasterURI http://master-server.example.com/repo > </Location> > > 3. Ensure the slave repository is a synced mirror of the master > (via svnsync). > > 4. Attempt a COPY operation through the slave to create a branch: > > svn copy http://slave-server.example.com/svn/repo/trunk \ > http://slave-server.example.com/svn/repo/branches/new-feature > \ > -m "Creating new feature branch" > > > EXPECTED RESULT > =============== > > The COPY request is proxied to the master and the branch is created > successfully. > > > ACTUAL RESULT > ============= > > The operation fails with HTTP 400 Bad Request. Server logs show the > master receiving a Destination header with path > /svn/repo/branches/new-feature which does not exist on the master > (the correct path would be /repo/branches/new-feature). > > > ROOT CAUSE > ========== > > In subversion/mod_dav_svn/mirror.c, the proxy_request_fixup() function > correctly rewrites the Request-URI when proxying requests to the master. > However, WebDAV COPY and MOVE operations specify their destination in > the Destination HTTP header, which is not rewritten. > > The existing filters handle: > - Request body rewriting (dav_svn__location_in_filter) > - Response body rewriting (dav_svn__location_body_filter) > - Response Location header rewriting (dav_svn__location_header_filter) > > But there is no rewriting for the incoming Destination request header. > > When paths are identical on slave and master, this bug is masked > because the path portion extracted from the Destination header happens > to be valid on both servers. The bug only manifests when the repository > paths differ. > > > FIX > === > > The attached patch adds rewriting of the Destination header in > proxy_request_fixup(). It parses the header, replaces the slave's root > path with the master's path, and updates the header before the request > is proxied. > > I have tested this fix and can confirm it fixes the issue in my testing. > > Please review the attached patch. > > Thanks, > Jordan Peck >
