One interesting change of TFS source control provider behavior in Visual Studio 2008 is the handling of writable files.
In VS2005, if you make certain source controlled file writable locally, editing it will not cause check out (you will have to explicitly check the file out); of course that assumes that VS is set either to explicitly or automatically check out file on edit or save.
With the same VS settings in VS2008, you will still be prompted to check out the file, even if it is writable. TFS source control provider tracks all controlled files in the solution, regardless of their read-only status.
The rational behind this change is clear – changing files locally without referencing source control repository may lead to changes never propagating to repository at all (and thus problems of “I have changed the file and it was not checked in” kind may arise).
However, there are some interesting problems you might encounter with that new behavior. Let’s say certain file is locked by someone else (with exclusive check-out lock). In VS2005 you would make this file writable locally, and VS would be happy to let you edit the file. In VS2008, however, VS will first check the status of the file in source control, and seeing that it is locked won’t allow you to edit this file.
There is workaround to this (aside from not ever messing up with local files modifications :); “Tools->Options->Source Control->Environment” tab in Visual Studio may be used to tweak the options. Setting checked-in items “Editing” behavior to “Do nothing” will allow you to edit file regardless of its status in source control (setting “Saving” behavior to “Save As” will allow you to save it). But keep in mind that this setting is probably very unproductive choice for day-to-day work.
Thanks for this tip go to Richard Berg.