--- a/mercurial/cmdutil.py Sat Aug 30 02:47:59 2014 +0200
+++ b/mercurial/cmdutil.py Sat Aug 30 01:48:58 2014 +0200
@@ -2518,12 +2518,22 @@
# file state
# action
# make backup
+
+ ## Sets that results that will change file on disk
+ # Modified compared to target, no local change
(modified, actions['revert'], discard),
+ # Modified compared to target, local change
(dsmodified, actions['revert'], backup),
+ # Added since target
(dsadded, actions['remove'], backup),
+ # Removed since target, before working copy parent
(removed, actions['add'], backup),
+ # Removed since targe, marked as such in working copy parent
(dsremoved, actions['undelete'], backup),
+ ## the following sets does not result in any file changes
+ # File with no modification
(clean, actions['noop'], discard),
+ # Existing file, not tracked anywhere
(unknown, actions['unknown'], discard),
)