Creating a patch is very easy in SubVersion, With Tortoise, you right-click and select Create Patch. But for the life of me, I can't find this functionality in TFS. Is this possible?
If not, what's the standard way to submit patches in open source TFS hosted projects (a la CodePlex)?
tf diff /shelveset:shelveset /format:unified
Edit: This writes to standard output. You can pipe the output to a file.
For more options, see Difference Command.
Codeplex uses its own client for creating patches. See: http://www.codeplex.com/CodePlexClient/Wiki/View.aspx?title=HowToContribute&referringTitle=Home
Because TFS doesn't natively support patch files, the most common thing I see people do on CodePlex is simply zip the modified files and upload the zip. The project coordinator then does a diff against their own checkout.
However since CodePlex also supports TortoiseSVN, more and more people are using that to create their patch files.
I wrote a blog post about a similar issue where I used the TF.exe command and 7Zip to create a TFS patch file that could then be applied on another TFS server or workspace. I posted the the Powershell scripts at Github, which can be used to Zip up any pending changes on one workspace and then apply them to a different server. It would have to be modified to use a changeset instead of pending changes, but that shouldn't be too difficult to accomplish.