Why does svn merge skip files

If you are using this method to merge a feature branch back to trunk, you need to start the merge wizard from within a working copy of trunk. In the From: field enter the full folder URL of the trunk.

This may sound wrong, but remember that the trunk is the start point to which you want to add the branch changes. In the To: field enter the full folder URL of the feature branch. In both the From Revision field and the To Revision field, enter the last revision number at which the two trees were synchronized. If you are sure no-one else is making commits you can use the HEAD revision in both cases.

If there is a chance that someone else may have made a commit since that synchronization, use the specific revision number to avoid losing more recent commits. This page of the wizard lets you specify advanced options, before starting the merge process. Most of the time you can just use the default settings. You can specify the depth to use for the merge, i. The default depth is Working copy , which uses the existing depth setting, and is almost always what you want.

Most of the time you want merge to take account of the file's history, so that changes relative to a common ancestor are merged. Sometimes you may need to merge files which are perhaps related, but not in your repository. For example you may have imported versions 1 and 2 of a third party library into two separate directories. Although they are logically related, Subversion has no knowledge of this because it only sees the tarballs you imported.

If you attempt to merge the difference between these two trees you would see a complete removal followed by a complete add. To make Subversion use only path-based differences rather than history-based differences, check the Ignore ancestry box.

Read more about this topic in the Subversion book, Noticing or Ignoring Ancestry. You can specify the way that line ending and whitespace changes are handled.

The default behaviour is to treat all whitespace and line-end differences as real changes to be merged. The checkbox marked Force the merge is used to avoid a tree conflict where an incoming delete affects a file that is either modified locally or not versioned at all.

If the file is deleted then there is no way to recover it, which is why that option is not checked by default. If you are using merge tracking and you want to mark a revision as having been merged, without actually doing the merge here, check the Only record the merge checkbox. There are two possible reasons you might want to do this. It may be that the merge is too complicated for the merge algorithms, so you code the changes by hand, then mark the change as merged so that the merge tracking algorithm is aware of it.

Or you might want to prevent a particular revision from being merged. Marking it as already merged will prevent the merge occurring with merge-tracking-aware clients. Now everything is set up, all you have to do is click on the Merge button. If you want to preview the results Test Merge simulates the merge operation, but does not modify the working copy at all. It shows you a list of the files that will be changed by a real merge, and notes files where conflicts may occur.

Because merge tracking makes the merge process a lot more complicated, there is no guaranteed way to find out in advance whether the merge will complete without conflicts, so files marked as conflicted in a test merge may in fact merge without any problem. The merge progress dialog shows each stage of the merge, with the revision ranges involved. This may indicate one more revision than you were expecting. To understand this you need to remember that Merge is closely related to Diff.

The merge process works by generating a list of differences between two points in the repository, and applying those differences to your working copy. The progress dialog is simply showing the start and end points for the diff. The merge is now complete.

It's a good idea to have a look at the merge and see if it's as expected. Merging is usually quite complicated.

Conflicts often arise if the branch has drifted far from the trunk. Whenever revisions are merged into a working copy, TortoiseSVN generates a log message from all the merged revisions.

Those are then available from the Recent Messages button in the commit dialog. To customize that generated message, set the corresponding project properties on your working copy. For Subversion clients and servers prior to 1. When you have tested the changes and come to commit this revision, your commit log message should always include the revision numbers which have been ported in the merge. If you want to apply another merge at a later time you will need to know what you have already merged, as you do not want to port a change more than once.

For more information about this, refer to Best Practices for Merging in the Subversion book. If you ask svn merge to compare the two trees, you'd see the entire first tree being deleted, followed by an add of the entire second tree!

In these situations, you'll want svn merge to do a path-based comparison only, ignoring any relations between files and directories. Add the --ignore-ancestry option to your merge command, and it will behave just like svn diff. And conversely, the --notice-ancestry option will cause svn diff to behave like the svn merge command. A common desire is to refactor source code, especially in Java-based software projects. Files and directories are shuffled around and renamed, often causing great disruption to everyone working on the project.

Sounds like a perfect case to use a branch, doesn't it? Just create a branch, shuffle things around, and then merge the branch back to the trunk, right?

Alas, this scenario doesn't work so well right now and is considered one of Subversion's current weak spots. The problem is that Subversion's svn update command isn't as robust as it should be, particularly when dealing with copy and move operations. When you use svn copy to duplicate a file, the repository remembers where the new file came from, but it fails to transmit that information to the client which is running svn update or svn merge.

This can lead to problems, especially because the same thing happens with renamed files. For example, suppose that while working on your private branch, you rename integer.

Effectively you've created a new file in your branch that is a copy of the original file, and deleted the original file. Meanwhile, back on trunk , Sally has committed some improvements to integer. Now you decide to merge your branch to the trunk:. This doesn't look so bad at first glance, but it's also probably not what you or Sally expected. The merge operation has deleted the latest version of the integer. This isn't true data loss. Sally's changes are still in the repository's history, but it may not be immediately obvious that this has happened.

The moral of this story is that until Subversion improves, be very careful about merging copies and renames from one branch to another. If you've just upgraded your server to Subversion 1. Why is this? When a pre So the subsequent commit, despite being the result of a merge, doesn't tell the repository about the duplicated changes—that information is lost. If you and your team are relying on the merge-tracking features of Subversion, you may want to configure your repository to prevent older clients from committing changes.

If the client reports itself as having mergeinfo capabilities, the hook script can allow the commit to start. If the client doesn't report that capability, have the hook deny the commit.

Example 4. Merge-tracking gatekeeper start-commit hook script. The bottom line is that Subversion's merge-tracking feature has an extremely complex internal implementation, and the svn:mergeinfo property is the only window the user has into the machinery. Because the feature is relatively new, a numbers of edge cases and possible unexpected behaviors may pop up. Sometimes mergeinfo will appear on files that you didn't expect to be touched by an operation. Sometimes mergeinfo won't be generated at all, when you expect it to.

We've chosen not to cover these detailed topics in this book for a couple of reasons. First, the level of detail is absolutely overwhelming for a typical user. Second, as Subversion continues to improve, we feel that a typical user shouldn't have to understand these concepts; they'll eventually fade into the background as pesky implementation details.

For now, if you want to steer clear of bugs and odd behaviors in automatic merging, the CollabNet article recommends that you stick to these simple best practices:. A merge target should be a working copy which represents a single location in the repository at a single point in time.

Always make sure you have complete read access to all of your merge sources, and that your target working copy has no sparse directories. This behavior may improve in future versions of Subversion. We would have to use the --ignore-ancestry option to make the merge command ignore the existing mergeinfo! You are reading Version Control with Subversion for Subversion 1.

Fitzpatrick, and C. Michael Pilato. This work is licensed under the Creative Commons Attribution License v2. Advanced Merging Prev Chapter 4.

Branching and Merging Next. Advanced Merging. U integer. Warning Did you notice how, in the last example, the merge invocation caused two distinct ranges of merges to be applied? For example, svn merge requires a working copy path as a target, that is, a place where it should apply the generated patch.

If the target isn't specified, it assumes you are trying to perform one of the following common operations:. You want to merge the changes in a specific file into a file by the same name that exists in your current working directory. If you are merging a directory and haven't specified a target path, svn merge assumes the first case and tries to apply the changes into your current directory.

If you are merging a file, and that file or a file by the same name exists in your current working directory, svn merge assumes the second case and tries to apply the changes to a local file with the same name. You've now seen some examples of the svn merge command, and you're about to see several more.

If you're feeling confused about exactly how merging works, you're not alone. Many users especially those new to version control are initially perplexed about the proper syntax of the command and about how and when the feature should be used. But fear not, this command is actually much simpler than you think! There's a very easy technique for understanding exactly how svn merge behaves.

The main source of confusion is the name of the command. That's not the case. A better name for the command might have been svn diff-and-apply , because that's all that happens: two repository trees are compared, and the differences are applied to a working copy.

If you're using svn merge to do basic copying of changes between branches, it will generally do the right thing automatically. For example, a command such as the following:. The command is smart enough to only duplicate changes that your working copy doesn't yet have. If you choose to use the svn merge command in all its full glory by giving it specific revision ranges to duplicate, the command takes three main arguments:.

An initial repository tree often called the left side of the comparison. A final repository tree often called the right side of the comparison. A working copy to accept the differences as local changes often called the target of the merge. Once these three arguments are specified, then the two trees are compared and the differences applied to the target working copy as local modifications. When the command is done, the results are no different than if you had hand-edited the files or run various svn add or svn delete commands yourself.

If you like the results, you can commit them. If you don't like the results, you can simply svn revert all of the changes.

The syntax of svn merge allows you to specify the three necessary arguments rather flexibly. Here are some examples:. The first syntax lays out all three arguments explicitly, naming each tree in the form URL REV and naming the working copy target.

The second syntax is used as a shorthand for situations when you're comparing two different revisions of the same URL. The last syntax shows how the working copy argument is optional; if omitted, it defaults to the current directory. The next section talks a bit more about this. Subversion tries to generate merge metadata whenever it can, to make future invocations of svn merge smarter.

There are still situations, however, where svn:mergeinfo data is not created or changed. Remember to be a bit wary of these scenarios:. If you ask svn merge to compare two URLs that aren't related to each other, a patch is still generated and applied to your working copy, but no merging metadata is created. At the time of this writing, Subversion has no way of representing different repository URLs within the svn:mergeinfo property.

If this option is passed to svn merge , it causes the merging logic to mindlessly generate differences the same way that svn diff does, ignoring any historical relationships. If this technique is used to undo a change to an object's personal history e. While implicit mergeinfo is largely an implementation detail, it can be a useful abstraction for understanding merge tracking behavior.

With each new revision added to the repository, the natural history—and thus, implicit mergeinfo—of the branch continues to expand to include those revisions until the day the branch is deleted. Here's what the implicit mergeinfo of our branch would look like when the HEAD revision of the repository had grown to Implicit mergeinfo does not actually show up in the svn:mergeinfo property, but Subversion acts as if it does. After all, avoiding repeated merges of changes is the primary goal of Subversion's merge tracking feature!

Just like the svn update command, svn merge applies changes to your working copy. And therefore it's also capable of creating conflicts.

The conflicts produced by svn merge , however, are sometimes different, and this section explains those differences. To begin with, assume that your working copy has no local edits.

The server produces the delta by comparing two trees: a virtual snapshot of your working copy, and the revision tree you're interested in.

Because the left hand side of the comparison is exactly equal to what you already have, the delta is guaranteed to correctly convert your working copy into the right hand tree.

But svn merge has no such guarantees and can be much more chaotic: the advanced user can ask the server to compare any two trees at all, even ones that are unrelated to the working copy! This means there's large potential for human error. Users will sometimes compare the wrong two trees, creating a delta that doesn't apply cleanly.

The svn merge subcommand does its best to apply as much of the delta as possible, but some parts may be impossible. A common sign that you merged the wrong delta is unexpected tree conflicts:. In the previous example, it might be the case that bar. The resultant delta wants to change the contents of the corresponding paths in your working copy, but those paths don't exist in the working copy. The main source of confusion is the name of the command. That's not the case. A better name for the command might have been svn diff-and-apply , because that's all that happens: two repository trees are compared, and the differences are applied to a working copy.

An initial repository tree often called the left side of the comparison ,. A final repository tree often called the right side of the comparison ,.

A working copy to accept the differences as local changes often called the target of the merge. Once these three arguments are specified, the two trees are compared, and the resulting differences are applied to the target working copy as local modifications. When the command is done, the results are no different than if you had hand-edited the files, or run various svn add or svn delete commands yourself.

If you like the results, you can commit them. If you don't like the results, you can simply svn revert all of the changes. The syntax of svn merge allows you to specify the three necessary arguments rather flexibly. Here are some examples:. The first syntax lays out all three arguments explicitly, naming each tree in the form URL REV and naming the working copy target. The second syntax can be used as a shorthand for situations when you're comparing two different revisions of the same URL.

The last syntax shows how the working-copy argument is optional; if omitted, it defaults to the current directory. Merging changes sounds simple enough, but in practice it can become a headache. The problem is that if you repeatedly merge changes from one branch to another, you might accidentally merge the same change twice. When this happens, sometimes things will work fine. When patching a file, Subversion typically notices if the file already has the change, and does nothing. But if the already-existing change has been modified in any way, you'll get a conflict.

Ideally, your version control system should prevent the double-application of changes to a branch. It should automatically remember which changes a branch has already received, and be able to list them for you. It should use this information to help automate merges as much as possible. Unfortunately, Subversion is not such a system. Like CVS, Subversion does not yet record any information about merge operations. When you commit local modifications, the repository has no idea whether those changes came from running svn merge , or from just hand-editing the files.

What does this mean to you, the user? It means that until the day Subversion grows this feature, you'll have to track merge information yourself.

The best place to do this is in the commit log-message. As demonstrated in the earlier example, it's recommended that your log-message mention a specific revision number or range of revisions that are being merged into your branch.

Later on, you can run svn log to review which changes your branch already contains. This will allow you to carefully construct a subsequent svn merge command that won't be redundant with previously ported changes. Because merging only results in local modifications, it's not usually a high-risk operation.

If you get the merge wrong the first time, simply svn revert the changes and try again. It's possible, however, that your working copy might already have local modifications. The changes applied by a merge will be mixed with your pre-existing ones, and running svn revert is no longer an option.