undo command

This commit was sponsored by Andrew Cant.

doc/git-annex.mdwn

@@ -282,6 +282,22 @@ subdirectories).
   are on a video hosting site, and the video is downloaded. This allows
   importing e.g., youtube playlists.
 
+* `undo [filename|directory] ...`
+
+  When passed a filename, undoes the last change that was made to that
+  file.
+
+  When passed a directory, undoes the last change that was made to the
+  contents of that directory.
+
+  Running undo a second time will undo the undo, returning the working
+  tree to the same state it had before. In order for undoing an undo of
+  staged changes, any staged changes are first committed by the
+  undo command.
+
+  Note that this does not undo get/drop of a file's content; it only
+  operates on the file tree committed to git.
+
 * `watch`
 
   Watches for changes to files in the current directory and its subdirectories,

doc/todo/direct_mode_undo.mdwn

@@ -80,5 +80,7 @@ the last change to each file would be expensive, and likely confusing.
 Instead, when a directory is passed, it could find the most recent commit
 that touched files in that directory, and undo the changes to those files.
 
+> [[done]] --[[Joey]]
+
 Also, --depth could make undo look for an older commit than the most
 recent one to affect the specified file.