Understanding Conflict Types

In software development teams where more than one person is working on the same project, it is common for conflict situations to be experienced. Team Foundation source control lets you resolve these conflicts. Conflicts can occur during the following operations:

• Merging changes between branches.

• Getting files into your workspace.

• Checking in new versions of files.

Conflict Types

This topic contains information about the following conflict types:

Version Conflict

File name collision conflict

Local overwrite conflict

Version Conflict

Version conflicts can occur in Team Foundation source control with a check in, get, or merge operation. In all three cases, the conflict results when an entity has evolved along divergent paths.

• Check-in   Two users check out the latest version of a file. The first user checks in changes creating a new version of the file. When the second user tries a check-in, a version conflict is experienced because their changes were not made against the latest version of the file.

• Get   Two users checkout the latest version of a file. The first user checks in changes creating a new version of the file. When the second user performs a get latest operation a version conflict is experienced because the get latest operation is trying to update the checked out file in their workspace.

• Merge   A file has been branched and has then been worked on in both branches. A user tries to merge changes from one branch to the other. A version conflict is experienced because the file has been modified on both branches.

Resolving version conflicts involves merging changes or selecting one set of changes over the other. For more information, see How to: Resolve Conflicts.

Version Conflicts

Local/Source Change	Server/Target Change	Resolve Options (Get or Checkin)	Resolve Options (Merge)
Edit Rename Undelete	Edit Rename Undelete	Merge changes for me (if there are no conflicts) Merge changes in merge tool Undo my local changes Discard server changes	Merge changes for me (if there are no conflicts) Merge changes in merge tool Keep changes in target branch Copy item from source branch This is the default selection.
	Delete	Restore file and merge changes for me (if there are no conflicts) Restore file and merge changes in merge tool Undo my local changes Restore file but keep my changes	Restore file and merge changes for me (if there are no conflicts) Restore file and merge changes in merge tool Discard changes from source branch Copy item from source branch
Delete	Edit Rename Undelete	Undo my local changes Discard server changes	Discard changes from source branch Delete item in target branch
	Delete	Undo my local changes	Discard changes from source branch
			Skip these conflicts (Indicates that conflicts of that type will not be acted upon.)

File Name Collision Conflict

File name collisions can occur in Team Foundation source control with a check-in, get, or merge operation. In all three cases, the conflict results when two or more items try to occupy the same path in the source control server.

• Check-in   Two users add a file that has the same name to an application they are working on together. The first user checks in the file, and when the second user tries a check-in, a file name collision is experienced.

• Get   Two users add a file that has the same name to an application they are working on together. The first user checks in the file, and when the second user tries a get latest operation a file name collision is experienced. This is because the first users file cannot be retrieved where the second user has added a file.

• Merge   An application has been branched and has then been worked on in both branches. In both branches, a file that has the same name has been added. A user tries to merge changes from one branch to the other. A file name collision is experienced because the file added to the source branch can not be branched where a file has already been added to the target branch.

File name collision can result from any operations that adds or moves items in the server path namespace, including add, rename, branch, undelete, and merge.

Resolving file name collisions involves selecting which item will ultimately occupy the source control server path. For more information, see How to: Resolve Conflicts.

File Name Collision Conflicts

Local/Source Change	Server/Target Change	Resolve Options (Get or Checkin)	Resolve Options(Merge)
Add Branch Rename Undelete	Add/ Branch Rename Undelete	Undo my local changes Ignore conflict	Discard changes from source branch Ignore conflict
			Skip these conflicts (Indicates that conflicts of that type will not be acted upon.) This is the default selection.

Local overwrite conflict

Local overwrite conflicts only occur in Team Foundation source control during a get operation. These conflicts occur when a get operation tries to write over a writable file in your workspace. By default, the get operation will only replace files that are read-only. Resolving local overwrite conflicts involves either overwriting the file, or checking out the file and merging changes.

Writable Files

Local/Source Change	Server/Target Change	Resolve Options (Get or Checkin)	Resolve Options(Merge)
Not applicable	Not applicable	Overwrite local file/folder Ignore conflict	Not applicable
			Skip These conflicts (Indicates that conflicts of that type will not be acted upon.) This is the default selection.

Note

Version conflicts that require a merge tool for resolution cannot be resolved from the Resolve Selected Conflicts dialog box. This dialog box does not contain the option to merge changes in a merge tool. Additionally, if you select Merge changes for me and internal content conflicts exist, the merge tool is not invoked. Instead, you are presented with the Unresolved Conflicts dialog box explaining that some files must be resolved individually. If only one file cannot be resolved, the dialog box includes the filename, if more than one file can not be resolved, then the dialog box will include the number of files.

The compare options are described in the following table:

Conflict Type	Source Change	Compare Options (Get or Checkin)	Compare Options (Merge)
Version	Edit Rename Undelete	Local to Server Local to Original Server to Original	Source to Target Source to Base Target to Base
		Local to Deleted Local to Original Deleted to Original	Source to Deleted Source to Base Deleted to Base
	Delete	Original to Server	Deleted to Target
		Not applicable	Not applicable
Filename Collision	Add Branch Rename Undelete	Local to Server	Source to Target
Writable File	Not applicable	Not applicable	Not applicable

See Also

Tasks

How to: Resolve Conflicts
How to: Get the Source for your Team Project
How to: Check In Pending Changes

Other Resources

Resolving Conflicts (Team Foundation Source Control)