view tests/test-patch-offset.t @ 35023:3649c3f2cd90

revert: do not reverse hunks in interactive when REV is not parent (issue5096)

And introduce a new "apply" operation verb for this case as suggested in
issue5096. This replaces the no longer used "revert" operation.

In interactive revert, when reverting to something else that the parent
revision, display an "apply this change" message with a diff that is not
reversed.

The rationale is that `hg revert -i -r REV` will show hunks of the diff from
the working directory to REV and prompt the user to select them for applying
(to working directory). This contradicts dcc56e10c23b in which it was
decided to have the "direction" of prompted hunks reversed. Later on
[1], there was a broad consensus (but no decision) towards the "as to
be applied direction". Now that --interactive is no longer experimental
(5910db5d1913), it's time to switch and thus we drop no longer used
"experimental.revertalternateinteractivemode" configuration option.

[1]: https://www.mercurial-scm.org/pipermail/mercurial-devel/2016-November/090142.html


.. feature::

  When interactive revert is run against a revision other than the working
  directory parent, the diff shown is the diff to *apply* to the working directory,
  rather than the diff to *discard* from the working copy. This is in line with
  related user experiences with `git` and appears to be less confusing with
  `ui.interface=curses`.

  $ cat > writepatterns.py <<EOF
  > import sys
  > 
  > path = sys.argv[1]
  > patterns = sys.argv[2:]
  > 
  > fp = file(path, 'wb')
  > for pattern in patterns:
  >     count = int(pattern[0:-1])
  >     char = pattern[-1] + '\n'
  >     fp.write(char*count)
  > fp.close()
  > EOF

prepare repo

  $ hg init a
  $ cd a

These initial lines of Xs were not in the original file used to generate
the patch.  So all the patch hunks need to be applied to a constant offset
within this file.  If the offset isn't tracked then the hunks can be
applied to the wrong lines of this file.

  $ $PYTHON ../writepatterns.py a 34X 10A 1B 10A 1C 10A 1B 10A 1D 10A 1B 10A 1E 10A 1B 10A
  $ hg commit -Am adda
  adding a

This is a cleaner patch generated via diff
In this case it reproduces the problem when
the output of hg export does not
import patch

  $ hg import -v -m 'b' -d '2 0' - <<EOF
  > --- a/a	2009-12-08 19:26:17.000000000 -0800
  > +++ b/a	2009-12-08 19:26:17.000000000 -0800
  > @@ -9,7 +9,7 @@
  >  A
  >  A
  >  B
  > -A
  > +a
  >  A
  >  A
  >  A
  > @@ -53,7 +53,7 @@
  >  A
  >  A
  >  B
  > -A
  > +a
  >  A
  >  A
  >  A
  > @@ -75,7 +75,7 @@
  >  A
  >  A
  >  B
  > -A
  > +a
  >  A
  >  A
  >  A
  > EOF
  applying patch from stdin
  patching file a
  Hunk #1 succeeded at 43 (offset 34 lines).
  Hunk #2 succeeded at 87 (offset 34 lines).
  Hunk #3 succeeded at 109 (offset 34 lines).
  committing files:
  a
  committing manifest
  committing changelog
  created 189885cecb41

compare imported changes against reference file

  $ $PYTHON ../writepatterns.py aref 34X 10A 1B 1a 9A 1C 10A 1B 10A 1D 10A 1B 1a 9A 1E 10A 1B 1a 9A
  $ diff aref a

  $ cd ..