rebase: add --stop option to stop rebase at any point (issue5206)

rebase: add --stop option to stop rebase at any point (issue5206)

Before this patch, during a rebase if you get a point where you can't
figure out what to do next, then either you had to complete your series
or abandon all the work you have done during this rebase.

Now, with this feature you can stop at any point by keeping the rebased
csets and mark original csets as obsolete. And if you don't have evolution
extension enabled then you can use --keep option as an alternative which
will keep original csets too, instead of marking them obsolete.

Differential Revision: https://phab.mercurial-scm.org/D3959

--- a/hgext/rebase.py	Fri Jun 01 11:36:06 2018 +0200
+++ b/hgext/rebase.py	Wed Jul 18 00:25:52 2018 +0530
@@ -673,6 +673,7 @@
     ('D', 'detach', False, _('(DEPRECATED)')),
     ('i', 'interactive', False, _('(DEPRECATED)')),
     ('t', 'tool', '', _('specify merge tool')),
+    ('', 'stop', False, _('stop interrupted rebase')),
     ('c', 'continue', False, _('continue an interrupted rebase')),
     ('a', 'abort', False, _('abort an interrupted rebase')),
     ('', 'auto-orphans', '', _('automatically rebase orphan revisions '
@@ -803,6 +804,7 @@
     opts = pycompat.byteskwargs(opts)
     inmemory = ui.configbool('rebase', 'experimental.inmemory')
     dryrun = opts.get('dry_run')
+    stop = opts.get('stop')
     if dryrun:
         if opts.get('abort'):
             raise error.Abort(_('cannot specify both --dry-run and --abort'))
@@ -835,6 +837,27 @@
 
     if dryrun:
         return _dryrunrebase(ui, repo, opts)
+    elif stop:
+        rbsrt = rebaseruntime(repo, ui)
+        rbsrt.restorestatus()
+
+        #todo: raise error for conflicting options
+        if rbsrt.collapsef:
+            raise error.Abort(_("cannot stop in --collapse session"))
+        allowunstable = obsolete.isenabled(repo, obsolete.allowunstableopt)
+        if not (rbsrt.keepf or allowunstable):
+            raise error.Abort(_("cannot remove original changesets with"
+                                " unrebased descendants"),
+                hint=_('either enable obsmarkers to allow unstable '
+                       'revisions or use --keep to keep original '
+                       'changesets'))
+        with repo.wlock(), repo.lock():
+            if needupdate(repo, rbsrt.state):
+                # update to the current working revision
+                # to clear interrupted merge
+                hg.updaterepo(repo, rbsrt.originalwd, overwrite=True)
+            rbsrt._finishrebase()
+            return 0
     elif inmemory:
         try:
             # in-memory merge doesn't support conflicts, so if we hit any, abort

--- a/tests/test-rebase-obsolete.t	Fri Jun 01 11:36:06 2018 +0200
+++ b/tests/test-rebase-obsolete.t	Wed Jul 18 00:25:52 2018 +0530
@@ -15,6 +15,7 @@
   > [extensions]
   > rebase=
   > drawdag=$TESTDIR/drawdag.py
+  > strip=
   > EOF
 
 Setup rebase canonical repo
@@ -1788,3 +1789,217 @@
   |
   o  0:426bada5c675 A
   
+====================
+Test --stop option |
+====================
+  $ cd ..
+  $ hg init rbstop
+  $ cd rbstop
+  $ echo a>a
+  $ hg ci -Aqma
+  $ echo b>b
+  $ hg ci -Aqmb
+  $ echo c>c
+  $ hg ci -Aqmc
+  $ echo d>d
+  $ hg ci -Aqmd
+  $ hg up 0 -q
+  $ echo f>f
+  $ hg ci -Aqmf
+  $ echo D>d
+  $ hg ci -Aqm "conflict with d"
+  $ hg up 3 -q
+  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
+  o  5:00bfc9898aeb test
+  |  conflict with d
+  |
+  o  4:dafd40200f93 test
+  |  f
+  |
+  | @  3:055a42cdd887 test
+  | |  d
+  | |
+  | o  2:177f92b77385 test
+  | |  c
+  | |
+  | o  1:d2ae7f538514 test
+  |/   b
+  |
+  o  0:cb9a9f314b8b test
+     a
+  
+  $ hg rebase -s 1 -d 5
+  rebasing 1:d2ae7f538514 "b"
+  rebasing 2:177f92b77385 "c"
+  rebasing 3:055a42cdd887 "d"
+  merging d
+  warning: conflicts while merging d! (edit, then use 'hg resolve --mark')
+  unresolved conflicts (see hg resolve, then hg rebase --continue)
+  [1]
+  $ hg rebase --stop
+  1 new orphan changesets
+  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
+  o  7:7fffad344617 test
+  |  c
+  |
+  o  6:b15528633407 test
+  |  b
+  |
+  o  5:00bfc9898aeb test
+  |  conflict with d
+  |
+  o  4:dafd40200f93 test
+  |  f
+  |
+  | @  3:055a42cdd887 test
+  | |  d
+  | |
+  | x  2:177f92b77385 test
+  | |  c
+  | |
+  | x  1:d2ae7f538514 test
+  |/   b
+  |
+  o  0:cb9a9f314b8b test
+     a
+  
+Test it aborts if unstable csets is not allowed:
+===============================================
+  $ cat >> $HGRCPATH << EOF
+  > [experimental]
+  > evolution.allowunstable=False
+  > EOF
+
+  $ hg strip 6 --no-backup -q
+  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
+  o  5:00bfc9898aeb test
+  |  conflict with d
+  |
+  o  4:dafd40200f93 test
+  |  f
+  |
+  | @  3:055a42cdd887 test
+  | |  d
+  | |
+  | o  2:177f92b77385 test
+  | |  c
+  | |
+  | o  1:d2ae7f538514 test
+  |/   b
+  |
+  o  0:cb9a9f314b8b test
+     a
+  
+  $ hg rebase -s 1 -d 5
+  rebasing 1:d2ae7f538514 "b"
+  rebasing 2:177f92b77385 "c"
+  rebasing 3:055a42cdd887 "d"
+  merging d
+  warning: conflicts while merging d! (edit, then use 'hg resolve --mark')
+  unresolved conflicts (see hg resolve, then hg rebase --continue)
+  [1]
+  $ hg rebase --stop
+  abort: cannot remove original changesets with unrebased descendants
+  (either enable obsmarkers to allow unstable revisions or use --keep to keep original changesets)
+  [255]
+  $ hg rebase --abort
+  saved backup bundle to $TESTTMP/rbstop/.hg/strip-backup/b15528633407-6eb72b6f-backup.hg
+  rebase aborted
+
+Test --stop when --keep is passed:
+==================================
+  $ hg rebase -s 1 -d 5 --keep
+  rebasing 1:d2ae7f538514 "b"
+  rebasing 2:177f92b77385 "c"
+  rebasing 3:055a42cdd887 "d"
+  merging d
+  warning: conflicts while merging d! (edit, then use 'hg resolve --mark')
+  unresolved conflicts (see hg resolve, then hg rebase --continue)
+  [1]
+  $ hg rebase --stop
+  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
+  o  7:7fffad344617 test
+  |  c
+  |
+  o  6:b15528633407 test
+  |  b
+  |
+  o  5:00bfc9898aeb test
+  |  conflict with d
+  |
+  o  4:dafd40200f93 test
+  |  f
+  |
+  | @  3:055a42cdd887 test
+  | |  d
+  | |
+  | o  2:177f92b77385 test
+  | |  c
+  | |
+  | o  1:d2ae7f538514 test
+  |/   b
+  |
+  o  0:cb9a9f314b8b test
+     a
+  
+Test --stop aborts when --collapse was passed:
+=============================================
+  $ cat >> $HGRCPATH << EOF
+  > [experimental]
+  > evolution.allowunstable=True
+  > EOF
+
+  $ hg strip 6
+  saved backup bundle to $TESTTMP/rbstop/.hg/strip-backup/b15528633407-6eb72b6f-backup.hg
+  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
+  o  5:00bfc9898aeb test
+  |  conflict with d
+  |
+  o  4:dafd40200f93 test
+  |  f
+  |
+  | @  3:055a42cdd887 test
+  | |  d
+  | |
+  | o  2:177f92b77385 test
+  | |  c
+  | |
+  | o  1:d2ae7f538514 test
+  |/   b
+  |
+  o  0:cb9a9f314b8b test
+     a
+  
+  $ hg rebase -s 1 -d 5 --collapse -m "collapsed b c d"
+  rebasing 1:d2ae7f538514 "b"
+  rebasing 2:177f92b77385 "c"
+  rebasing 3:055a42cdd887 "d"
+  merging d
+  warning: conflicts while merging d! (edit, then use 'hg resolve --mark')
+  unresolved conflicts (see hg resolve, then hg rebase --continue)
+  [1]
+  $ hg rebase --stop
+  abort: cannot stop in --collapse session
+  [255]
+  $ hg rebase --abort
+  rebase aborted
+  $ hg diff
+  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
+  o  5:00bfc9898aeb test
+  |  conflict with d
+  |
+  o  4:dafd40200f93 test
+  |  f
+  |
+  | @  3:055a42cdd887 test
+  | |  d
+  | |
+  | o  2:177f92b77385 test
+  | |  c
+  | |
+  | o  1:d2ae7f538514 test
+  |/   b
+  |
+  o  0:cb9a9f314b8b test
+     a
+