D6125: revert: option to choose what to keep, not what to discard

[martinvonz (Martin von Zweigbergk)]

martinvonz created this revision.
Herald added a subscriber: mercurial-devel.
Herald added a reviewer: hg-reviewers.

REVISION SUMMARY
  I know the you (the reader) are probably tired of discussing how `hg
  revert -i -r .` should behave and so am I. And I know I'm one of the
  people who argued that showing the diff from the working copy to the
  parent was confusing. I think it is less confusing now that we show
  the diff from the parent to the working copy, but I still find it
  confusing. I think showing the diff of hunks to keep might make it
  easier to understand. So that's what this patch provides an option
  for.
  
  One argument doing it this way is that most people seem to find `hg
  split` natural. I suspect that is because it shows the forward diff
  (from parent commit to the commit) and asks you what to put in the
  first commit. I think the new "keep" mode for revert (this patch)
  matches that.
  
  In "keep" mode, all the changes are still selected by default. That
  means that `hg revert -i` followed by 'A' (keep all) (or 'c' in
  curses) will be different from `hg revert -a`. That's mostly because
  that was simplest. It can also be argued that it's safest. But it can
  also be argued that it should be consistent with `hg revert -a`.
  
  Note that in this mode, you can edit the hunks and it will do what you
  expect (e.g. add new lines to your file if you added a new lines when
  editing). The test case shows that that works.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D6125

AFFECTED FILES
  mercurial/cmdutil.py
  mercurial/configitems.py
  mercurial/crecord.py
  mercurial/patch.py
  tests/test-revert-interactive.t

CHANGE DETAILS

diff --git a/tests/test-revert-interactive.t b/tests/test-revert-interactive.t
--- a/tests/test-revert-interactive.t
+++ b/tests/test-revert-interactive.t
@@ -444,4 +444,52 @@
   > EOF
   add back removed file a (Yn)? n
   $ ls
+  $ hg revert -a
+  undeleting a
   $ cd ..
+
+Test "keep" mode
+
+  $ cat <<EOF >> $HGRCPATH
+  > [experimental]
+  > revert.interactive.select-to-keep = true
+  > EOF
+
+  $ cd repo
+  $ printf "x\na\ny\n" > a
+  $ hg diff
+  diff -r cb9a9f314b8b a
+  --- a/a	Thu Jan 01 00:00:00 1970 +0000
+  +++ b/a	Thu Jan 01 00:00:00 1970 +0000
+  @@ -1,1 +1,3 @@
+  +x
+   a
+  +y
+  $ cat > $TESTTMP/editor.sh << '__EOF__'
+  > echo "+new line" >> "$1"
+  > __EOF__
+
+  $ HGEDITOR="\"sh\" \"${TESTTMP}/editor.sh\"" hg revert -i  <<EOF
+  > y
+  > n
+  > e
+  > EOF
+  diff --git a/a b/a
+  2 hunks, 2 lines changed
+  examine changes to 'a'? [Ynesfdaq?] y
+  
+  @@ -1,1 +1,2 @@
+  +x
+   a
+  keep change 1/2 to 'a'? [Ynesfdaq?] n
+  
+  @@ -1,1 +2,2 @@
+   a
+  +y
+  keep change 2/2 to 'a'? [Ynesfdaq?] e
+  
+  reverting a
+  $ cat a
+  a
+  y
+  new line
diff --git a/mercurial/patch.py b/mercurial/patch.py
--- a/mercurial/patch.py
+++ b/mercurial/patch.py
@@ -1012,11 +1012,13 @@
         'multiple': {
             'apply': _("apply change %d/%d to '%s'?"),
             'discard': _("discard change %d/%d to '%s'?"),
+            'keep': _("keep change %d/%d to '%s'?"),
             'record': _("record change %d/%d to '%s'?"),
         },
         'single': {
             'apply': _("apply this change to '%s'?"),
             'discard': _("discard this change to '%s'?"),
+            'keep': _("keep this change to '%s'?"),
             'record': _("record this change to '%s'?"),
         },
         'help': {
@@ -1040,6 +1042,16 @@
                          '$$ Discard &all changes to all remaining files'
                          '$$ &Quit, discarding no changes'
                          '$$ &? (display help)'),
+            'keep': _('[Ynesfdaq?]'
+                         '$$ &Yes, keep this change'
+                         '$$ &No, skip this change'
+                         '$$ &Edit this change manually'
+                         '$$ &Skip remaining changes to this file'
+                         '$$ Keep remaining changes to this &file'
+                         '$$ &Done, skip remaining changes and files'
+                         '$$ Keep &all changes to all remaining files'
+                         '$$ &Quit, keeping all changes'
+                         '$$ &? (display help)'),
             'record': _('[Ynesfdaq?]'
                         '$$ &Yes, record this change'
                         '$$ &No, skip this change'
diff --git a/mercurial/crecord.py b/mercurial/crecord.py
--- a/mercurial/crecord.py
+++ b/mercurial/crecord.py
@@ -566,6 +566,7 @@
 _headermessages = { # {operation: text}
     'apply': _('Select hunks to apply'),
     'discard': _('Select hunks to discard'),
+    'keep': _('Select hunks to keep'),
     None: _('Select hunks to record'),
 }
 
diff --git a/mercurial/configitems.py b/mercurial/configitems.py
--- a/mercurial/configitems.py
+++ b/mercurial/configitems.py
@@ -595,6 +595,9 @@
 coreconfigitem('experimental', 'removeemptydirs',
     default=True,
 )
+coreconfigitem('experimental', 'revert.interactive.select-to-keep',
+    default=False,
+)
 coreconfigitem('experimental', 'revisions.prefixhexnode',
     default=False,
 )
diff --git a/mercurial/cmdutil.py b/mercurial/cmdutil.py
--- a/mercurial/cmdutil.py
+++ b/mercurial/cmdutil.py
@@ -3154,22 +3154,25 @@
                                          configprefix='revert.interactive.')
         diffopts.nodates = True
         diffopts.git = True
-        operation = 'discard'
-        reversehunks = True
-        if node != parent:
-            operation = 'apply'
-            reversehunks = False
-        if reversehunks:
+        operation = 'apply'
+        if node == parent:
+            if repo.ui.configbool('experimental',
+                                  'revert.interactive.select-to-keep'):
+                operation = 'keep'
+            else:
+                operation = 'discard'
+
+        if operation == 'apply':
+            diff = patch.diff(repo, None, ctx.node(), m, opts=diffopts)
+        else:
             diff = patch.diff(repo, ctx.node(), None, m, opts=diffopts)
-        else:
-            diff = patch.diff(repo, None, ctx.node(), m, opts=diffopts)
         originalchunks = patch.parsepatch(diff)
 
         try:
 
             chunks, opts = recordfilter(repo.ui, originalchunks,
                                         operation=operation)
-            if reversehunks:
+            if operation == 'discard':
                 chunks = patch.reversehunks(chunks)
 
         except error.PatchError as err:
@@ -3183,6 +3186,7 @@
         # chunks are serialized per file, but files aren't sorted
         for f in sorted(set(c.header.filename() for c in chunks if ishunk(c))):
             prntstatusmsg('revert', f)
+        files = set()
         for c in chunks:
             if ishunk(c):
                 abs = c.header.filename()
@@ -3192,6 +3196,10 @@
                     bakname = scmutil.backuppath(repo.ui, repo, abs)
                     util.copyfile(target, bakname)
                     tobackup.remove(abs)
+                if abs not in files:
+                    files.add(abs)
+                    if operation == 'keep':
+                        checkout(abs)
             c.write(fp)
         dopatch = fp.tell()
         fp.seek(0)



To: martinvonz, #hg-reviewers
Cc: mercurial-devel