When does svn BASE become equal to the HEAD

Question

I had a question regarding the BASE version in svn. I know it is the pristine version of an item from the last time update was run and svn diff and status basically run against this version. When does the BASE get updated? Does it get updated to the HEAD when update is run? Is this always true even if there was a conflict during update? What does BASE have incase of a conflict? Does it still have the version from my last update(before the most recent update that caused a conflict) or will it be updated to the HEAD even if there is a conflict?
Also when svn commit is run I am assuming the BASE gets updated with my local changes and at this point BASE, HEAD and my local copy all are the same? Provided the commit was successful.

Answer 1

HEAD is the latest revision in the repository. BASE is the last revision you have obtained from the repository. They are the same after a successful commit or update.

When you make changes, your files differ from the BASE copies. When you revert, they go back to matching the BASE revision. When you get a conflict, you do not update the repository. Rather, your files are considered to still be "being edited" as if you were making changes. After you resolve conflicts, you have in essence decided what the final files will look like and you then commit them as you would have normally. So, conflicts are like a case of special editing.