# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@fb.com>
# Date 1409482860 -7200
# Node ID 2ff28e07d7d6c27f0ce4f676776e33f0bd12a432
# Parent  0f323ed8effd86aabcc28faf9e453a94d500c8fe
revert: properly back up added files with local modification

These files were previously not backed up because the backup mechanism was not
smart enough. This leads to data lose for the user since uncommitted contents
were discarded.

We now properly move the modified version to <filename>.orig before deleting it.

We have to use a small hack to do a different action if "--no-backup" is
specified. This is needed because the backup process is actually a move (not a
copy) so the file is already missing when we backup. The internet kitten is a
bit disapointed about that, but such is life.

This patch concludes the "lets refactor revert" phases. We can now open the
"Lets find stupid bug with renames and merge" phases.

I'm sure that now that the code is clearer we could do it in another simpler
way, but I consider the current improvement good enough for now.

diff -r 0f323ed8effd -r 2ff28e07d7d6 mercurial/cmdutil.py
--- a/mercurial/cmdutil.py	Sat Aug 30 02:39:08 2014 +0200
+++ b/mercurial/cmdutil.py	Sun Aug 31 13:01:00 2014 +0200
@@ -2640,6 +2640,10 @@
         if opts.get('no_backup'):
             backup = check = discard
 
+        backupanddel = actions['remove']
+        if not opts.get('no_backup'):
+            backupanddel = actions['drop']
+
         disptable = (
             # dispatch table:
             #   file state
@@ -2658,7 +2662,7 @@
             # Added in working directory
             (dsadded,       actions['forget'],   discard),
             # Added since target, have local modification
-            (modadded,      actions['remove'],   discard),
+            (modadded,      backupanddel,        backup),
             # Added since target but file is missing in working directory
             (deladded,      actions['drop'],   discard),
             # Removed since  target, before working copy parent
diff -r 0f323ed8effd -r 2ff28e07d7d6 tests/test-revert.t
--- a/tests/test-revert.t	Sat Aug 30 02:39:08 2014 +0200
+++ b/tests/test-revert.t	Sun Aug 31 13:01:00 2014 +0200
@@ -940,16 +940,12 @@
 The diff is filtered to include change only. The only difference should be
 additional `.orig` backup file when applicable.
 
-Misbehavior:
-
-- no backup for
-| - added_wc (DATA LOSS)
-
   $ python ../dircontent.py > ../content-base-all.txt
   $ cd ..
   $ diff -U 0 -- content-base.txt content-base-all.txt | grep _
   +parent added_untracked-clean
   +wc     added_untracked-wc
+  +wc     added_wc.orig
   +wc     clean_untracked-wc.orig
   +wc     clean_wc.orig
   +wc     missing_untracked-wc