svn

# ignore certain files in the working directory
# opens up a text editor where you can type patterns to ignore
svn propedit svn:ignore app/tmp

# revert a messed up/deleted directory
svn revert adir --recursive

Branches and merging

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:

Merging unrelated sources

If you ask svn merge to compare two URLs that aren't related to each other, a patch will still be generated and applied to your working copy, but no merging metadata will be created. There's no common history between the two sources, and future “smart” merges depend on that common history.

Merging from foreign repositories

While it's possible to run a command such as svn merge -r 100:200 http://svn.foreignproject.com/repos/trunk, the resultant patch will also lack any historical merge metadata. At time of this writing, Subversion has no way of representing different repository URLs within the svn:mergeinfo property.

Using --ignore-ancestry

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. We discuss this later in the chapter in the section called “Noticing or Ignoring Ancestry”.

Applying reverse merges to a target's natural history

Earlier in this chapter (the section called “Undoing Changes”) we discussed how to use svn merge to apply a “reverse patch” as a way of rolling back changes. If this technique is used to undo a change to an object's personal history (e.g., commit r5 to the trunk, then immediately roll back r5 using svn merge . -c -5), this sort of merge doesn't affect the recorded mergeinfo. [23]