view tests/test-amend.t @ 3846:f9dad99a90d5

evolve: create a new commit instead of amending one of the divergents

This patch changes the behavior of evolve command while resolving
content-divergence to create a new commit instead of amending one of the
divergent ones.

In past, I have made this change, backed out this change and now today again I
am doing this change, so let's dive in some history.

Using cmdrewrite.amend() was never a good option as that requires hack to delete
the evolvestate and also gives us less control over things. We can't make the
commit on top of different parents as that of content-divergent ones. Due to all
these, I first made this change to create a new commit instead of amending one.

But, after few days, there was flakiness observed in the tests and turned out
that we need to do some dirstate dance as repo.dirstate.setparents() does not
always fix the dirstate. That flakiness was a blocker for progress at that time
and we decided to switch to amend back so that we can have things working with
some hacks and we can later fix the implementation part.

Now, yesterday while tackling resolving content-divergence of a stack which is
as follows:

C1 C2
 | |
B1 B2
 | |
A1 A2
 \/
base

where, A1-A2, B1-B2, C1-C2 are content-divergent with each other. Now we can
resolve A1-A2 very well because they have the same parent and let's say that
resolution leads to A3.
Now, we want to resolve B1-B2 and make the new resolution commit on top of A3 so
that we can end up something like:

C3
 |
B3
 |
A3
 |
base

however, amending one of the divergent changesets, it's not possible to create a
commit on a different parent like A3 here without some relocation. We should
prevent relocation as that may leads to some conflicts and should change the
parent before committing.

So, looking ahead, we can't move with using amend as still using that we will
need some relocation hacks making code ugly and prone to bad behaviors, bugs.
Let's change back to creating a new commit so that we can move forward in a good
way.

About repo.dirstate.setparents() not setting the dirstate, I have researched
yesterday night about how we can do that and found out that we can use
cmdrewrite._uncommitdirstate() here. Expect upcoming patches to improve the
documentation of that function.

There are lot of test changes because of change in hash but there is no behavior
change. The only behavior change is in test-evolve-abort-contentdiv.t which is
nice because creating a new commit helps us in stripping that while aborting.
We have a lot of testing of content-divergence and no behavior change gives
enough confidence for making this change.

I reviewed the patch carefully to make sure there is no behavior change and I
suggest reviewer to do the same.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > EOF
  $ echo "evolve=$(echo $(dirname $TESTDIR))/hgext3rd/evolve/" >> $HGRCPATH

  $ glog() {
  >   hg log -G --template '{rev}@{branch}({phase}) {desc|firstline}\n' "$@"
  > }

  $ hg init repo --traceback
  $ cd repo
  $ echo a > a
  $ hg ci -Am adda
  adding a

Test that amend captures branches

  $ hg branch foo
  marked working directory as branch foo
  (branches are permanent and global, did you want a bookmark?)
  $ hg amend -d '0 0' -n "this a note on the obsmarker and supported for hg>=4.4"
  $ hg debugobsolete
  07f4944404050f47db2e5c5071e0e84e7a27bba9 6a022cbb61d5ba0f03f98ff2d36319dfea1034ae 0 (*) {'ef1': '*', 'user': 'test'} (glob)
  $ hg obslog
  @  6a022cbb61d5 (1) adda
  |
  x  07f494440405 (0) adda
       rewritten(branch) as 6a022cbb61d5 using amend by test (Thu Jan 01 00:00:00 1970 +0000)
         note: this a note on the obsmarker and supported for hg>=4.4
  
  $ hg branch
  foo
  $ hg branches
  foo                            1:6a022cbb61d5
  $ glog
  @  1@foo(draft) adda
  
Test no-op

  $ hg amend -d '0 0'
  nothing changed
  [1]
  $ glog
  @  1@foo(draft) adda
  

Test forcing the message to the same value, no intermediate revision.

  $ hg amend -d '0 0' -m 'adda'
  nothing changed
  [1]
  $ glog
  @  1@foo(draft) adda
  

Test collapsing into an existing revision, no intermediate revision.

  $ echo a >> a
  $ hg ci -m changea
  $ echo a > a
  $ hg status
  M a
  $ hg pstatus
  $ hg diff
  diff -r f7a50201fe3a a
  --- a/a	Thu Jan 01 00:00:00 1970 +0000
  +++ b/a	* +0000 (glob)
  @@ -1,2 +1,1 @@
   a
  -a
  $ hg pdiff
  $ hg ci -m reseta
  $ hg debugobsolete
  07f4944404050f47db2e5c5071e0e84e7a27bba9 6a022cbb61d5ba0f03f98ff2d36319dfea1034ae 0 (*) {'ef1': '*', 'user': 'test'} (glob)
  $ hg phase 2
  2: draft
  $ glog
  @  3@foo(draft) reseta
  |
  o  2@foo(draft) changea
  |
  o  1@foo(draft) adda
  
Specify precise commit date with -d
  $ hg amend -d '2001-02-03 04:05:06 +0700'
  $ hg parents --template '{rev}  {date|date}\n'
  4  Sat Feb 03 04:05:06 2001 +0700

Specify "now" as commit date with -D
  $ before=`date +%s`
  $ hg amend -D
  $ commit=`hg parents --template '{date|hgdate} rev{rev}\n'`
  $ after=`date +%s`
  $ (echo $before ; echo $commit; echo $after) | sort -k1 -n -s
  \d+ (re)
  \d+ 0 rev5 (re)
  \d+ (re)

Specify current user as committer with -U
  $ HGUSER=newbie hg amend -U
  $ hg parents --template '{rev}  {author}\n'
  6  newbie

Check that --logfile works
  $ echo "logfile message" > logfile.txt
  $ hg amend -l logfile.txt
  $ hg log -r . -T "{desc}\n"
  logfile message

# Make sure we don't get reparented to -1 with no username (issue4211)
  $ HGUSER=
  $ hg amend -e --config ui.username= -m "empty user"
  abort: no username supplied
  (use 'hg config --edit' to set your username)
  [255]
  $ hg sum
  parent: 7:* tip (glob)
   logfile message
  branch: foo
  commit: 1 unknown (clean)
  update: (current)
  phases: 3 draft

Check the help
  $ hg amend -h
  hg amend [OPTION]... [FILE]...
  
  aliases: refresh
  
  combine a changeset with updates and replace it with a new one
  
      Commits a new changeset incorporating both the changes to the given files
      and all the changes from the current parent changeset into the repository.
  
      See 'hg commit' for details about committing changes.
  
      If you don't specify -m, the parent's message will be reused.
  
      If --extract is specified, the behavior of 'hg amend' is reversed: Changes
      to selected files in the checked out revision appear again as uncommitted
      changed in the working directory.
  
      Returns 0 on success, 1 if nothing changed.
  
  options ([+] can be repeated):
  
   -A --addremove           mark new/missing files as added/removed before
                            committing
   -a --all                 match all files
   -e --edit                invoke editor on commit messages
      --extract             extract changes from the commit to the working copy
      --patch               make changes to wdir parent by editing patch
      --close-branch        mark a branch as closed, hiding it from the branch
                            list
   -s --secret              use the secret phase for committing
   -n --note VALUE          store a note on amend
   -I --include PATTERN [+] include names matching the given patterns
   -X --exclude PATTERN [+] exclude names matching the given patterns
   -m --message TEXT        use text as commit message
   -l --logfile FILE        read commit message from file
   -d --date DATE           record the specified date as commit date
   -u --user USER           record the specified user as committer
   -D --current-date        record the current date as commit date
   -U --current-user        record the current user as committer
   -i --interactive         use interactive mode
  
  (some details hidden, use --verbose to show complete help)