Little tangent here, but FWIW I found that the version on the server supported merge tracking so it was super wierd that the whole codebase reported tree conflicts. I think we merged incorrectly a long time ago and this might have caused the conflicts. I just rebranched, problem solved, next step need to make sure we're merging correctly.
On Fri, Dec 9, 2011 at 7:00 AM, Stefan Sperling <s...@elego.de> wrote: > On Fri, Dec 09, 2011 at 01:05:02PM +0000, Rob Pointer wrote: > > Mark > > If you put changes multiple times from trunk to a branch (in development > > terms, a re-base) you can cause reflective merges and actually cause more > > problems. The recommended merge back into trunk is a reintegrate merge. > > I am not sure if this has been addressed in 1.7, but certainly for > earlier > > versions (anyone please correct me if I am wrong here though :) ). > > > > The scenario goes > > 1) trunk contains file A > > 2) copy trunk to branch1 > > 3) modify file A in branch1 > > 4) add folderb/fileb in trunk > > 5) branch (copy) folderb into branch (or merge if it actually works :) ) > > 6) do some changes to file A and ffileb > > 7) merge back into trunk. > > > > SVN seems to get confused and when it checks the history of both trunk > and > > branch1 it doesn't know that the folderb/fileb was added in branch1 > using a > > copy, therefore it just thinks you added the files on trunk and then > > branch1 as two separate operations (for any clearcase users this is an > evil > > twin scenario). Therefore SVN will create a tree conflict when merging > > your branch back into trunk. > > Wrong, wrong, wrong. You may believe that Subversion is broken but in > fact you're just pushing its buttons the wrong way. > > To be clear, if you use the correct merge syntax for each step your > scenario works just fine. And this applies to 1.6 as well as 1.7. > > To demonstrate: > > + rm -rf reflective-merge > + mkdir -p reflective-merge > + mkdir -p reflective-merge/trunk > + echo A > + > reflective-merge/trunk/A > + svnadmin create /tmp/reflective-merge/repos > + svn import reflective-merge/trunk > file:////tmp/reflective-merge/repos/trunk -m importing project tree > Adding reflective-merge/trunk/A > > Committed revision 1. > + svn copy file:////tmp/reflective-merge/repos/trunk > file:////tmp/reflective-merge/repos/branch1 -m creating branch > > Committed revision 2. > + rm -rf reflective-merge/trunk > + svn checkout file:////tmp/reflective-merge/repos/trunk > reflective-merge/trunk > A reflective-merge/trunk/A > Checked out revision 2. > + svn checkout file:////tmp/reflective-merge/repos/branch1 > reflective-merge/branch1 > A reflective-merge/branch1/A > Checked out revision 2. > + echo foo > + >> reflective-merge/branch1/A > + svn commit -m modify A on branch reflective-merge/branch1 > Sending reflective-merge/branch1/A > Transmitting file data . > Committed revision 3. > + svn mkdir reflective-merge/trunk/folderb > A reflective-merge/trunk/folderb > + echo bar > + >> reflective-merge/trunk/folderb/fileb > + svn commit -m add folderb/fileb on trunk reflective-merge/trunk > Adding reflective-merge/trunk/folderb > > Committed revision 4. > + svn update reflective-merge/branch1 > Updating 'reflective-merge/branch1': > At revision 4. > + svn merge file:////tmp/reflective-merge/repos/trunk > reflective-merge/branch1 --accept postpone > --- Merging r2 through r4 into 'reflective-merge/branch1': > A reflective-merge/branch1/folderb > --- Recording mergeinfo for merge of r2 through r4 into > 'reflective-merge/branch1': > U reflective-merge/branch1 > + svn commit reflective-merge/branch1 -m merge trunk into branch (no > conflicts) > Sending reflective-merge/branch1 > Adding reflective-merge/branch1/folderb > > Committed revision 5. > + echo baz > + >> reflective-merge/branch1/folderb/fileb > + svn commit -m modify folderb/fileb on branch reflective-merge/branch1 > + svn update reflective-merge/trunk > Updating 'reflective-merge/trunk': > At revision 5. > + svn merge --reintegrate file:////tmp/reflective-merge/repos/branch1 > reflective-merge/trunk --accept postpone > --- Merging differences between repository URLs into > 'reflective-merge/trunk': > U reflective-merge/trunk/A > --- Recording mergeinfo for merge between repository URLs into > 'reflective-merge/trunk': > U reflective-merge/trunk > + svn commit reflective-merge/trunk -m reintegrate branch into trunk (no > conflicts) > Sending reflective-merge/trunk > Sending reflective-merge/trunk/A > Transmitting file data . > Committed revision 6. > > You only get a tree-conflict if you forget to use --reintegrate in the last > merge: > > + svn update reflective-merge/trunk > Updating 'reflective-merge/trunk': > At revision 5. > + svn merge file:////tmp/reflective-merge/repos/branch1 > reflective-merge/trunk --accept postpone > --- Merging r2 through r5 into 'reflective-merge/trunk': > U reflective-merge/trunk/A > C reflective-merge/trunk/folderb > --- Recording mergeinfo for merge of r2 through r5 into > 'reflective-merge/trunk': > U reflective-merge/trunk > Summary of conflicts: > Tree conflicts: 1 > + svn commit reflective-merge/trunk -m reintegrate branch into trunk (no > conflicts) > subversion/svn/commit-cmd.c:183: (apr_err=155015) > subversion/libsvn_client/commit.c:853: (apr_err=155015) > subversion/libsvn_client/commit.c:853: (apr_err=155015) > svn: E155015: Commit failed (details follow): > subversion/libsvn_client/commit_util.c:1154: (apr_err=155015) > subversion/libsvn_client/commit_util.c:1154: (apr_err=155015) > subversion/libsvn_client/commit_util.c:823: (apr_err=155015) > subversion/libsvn_client/commit_util.c:329: (apr_err=155015) > svn: E155015: Aborting commit: '/tmp/reflective-merge/trunk/folderb' > remains in conflict > > To understand why you need the --reintegrate, see: > > http://mail-archives.apache.org/mod_mbox/subversion-dev/201107.mbox/%3c20110720124721.ga7...@ted.stsp.name%3E > > To understand how to repeatedly merge back and forth between the > trunk and the branch, see here: > > http://svnbook.red-bean.com/en/1.7/svn.branchmerge.advanced.html#svn.branchmerge.advanced.reintegratetwice > > For some reason understanding the --reintegrate option seems to be > a major usability hurdle for many when it comes to understanding merging > in Subversion. It would be nice to just make the 'svn merge ^/foobar' > magically do whatever people expect. But I don't see a good way of doing > that, unfortunately. > Once you understand what a 2-URL merge is and how that works, and that > any merge is really just a 2-URL merge, it's really not that hard to > understand that --reintegrate is just syntactic sugar and when you > should use it. > > > A similar scenario occurs of you copied file A from trunk to branch1 > after > > modifying it on trunk. SVN will then throw content conflicts, telling > you > > that you modified the same line in the file in two branches (i.e. trunk > > and branch1) and the text is identical. Again not sure if 1.7 fixes > this, > > but it is definitely present in 1.6.x > > Again, please verify that you're invoking the tool in the right way > before jumping to conclusions. > > If you don't carefully use the right 'svn merge' invokation syntax > for the situation at hand you can easily create conflicts for yourself. > See also the output of 'svn help merge' in 1.7, copied here: > http://subversion.apache.org/docs/svn-merge.txt >
