rebase: also include commit of collapsed commits in single transaction

When rebase.singletransaction is set, we still used to create a second
transaction when committing with --collapse. It's simpler to create a
single transaction.

Note that in the affected .t file, the test that uses --collapse still
appears to create two transactions (it prints "rebase status stored"
twice). However, only a single transaction is actually created and the
second printout comes from cmdutil.commitforceeditor() that explicitly
calls tr.writepending().

Also note the that we now roll back any commits if the user closes the
commit message editor with an error code (or leaves the message
empty). That might be unfortunate, but it's consistent with how we
behave in the --no-collapse case (if the user passed --edit). If we
want to change that, I think it should be done consistently in a
separate patch.

Differential Revision: https://phab.mercurial-scm.org/D2728

hgext/rebase.py

@@ -573,16 +573,12 b' class rebaseruntime(object):'
                     keepbranches=self.keepbranchesf,
                     date=self.date, wctx=self.wctx)
             else:
-                dsguard = None
-                if ui.configbool('rebase', 'singletransaction'):
-                    dsguard = dirstateguard.dirstateguard(repo, 'rebase')
-                with util.acceptintervention(dsguard):
-                    newnode = concludenode(repo, revtoreuse, p1, self.external,
-                        commitmsg=commitmsg,
-                        extrafn=_makeextrafn(self.extrafns),
-                        editor=editor,
-                        keepbranches=self.keepbranchesf,
-                        date=self.date)
+                newnode = concludenode(repo, revtoreuse, p1, self.external,
+                    commitmsg=commitmsg,
+                    extrafn=_makeextrafn(self.extrafns),
+                    editor=editor,
+                    keepbranches=self.keepbranchesf,
+                    date=self.date)
             if newnode is not None:
                 newrev = repo[newnode].rev()
                 for oldrev in self.state:
@@ -864,8 +860,7 b' def _origrebase(ui, repo, inmemory=False'
                 dsguard = dirstateguard.dirstateguard(repo, 'rebase')
             with util.acceptintervention(dsguard):
                 rbsrt._performrebase(tr)
-
-        rbsrt._finishrebase()
+                rbsrt._finishrebase()
 
 def _definedestmap(ui, repo, rbsrt, destf=None, srcf=None, basef=None,
                    revf=None, destspace=None):

tests/test-rebase-transaction.t

@@ -29,11 +29,9 b' Check that a simple rebase works'
   >   |/
   >   A
   > EOF
-- We should only see two status stored messages. One from the start, one from
-- the end.
+- We should only see one status stored message. It comes from the start.
   $ hg rebase --debug -b D -d Z | grep 'status stored'
   rebase status stored
-  rebase status stored
   $ hg tglog
   o  5: D
   |
@@ -64,7 +62,7 b' Check that --collapse works'
   >   A
   > EOF
 - We should only see two status stored messages. One from the start, one from
-- the end.
+- cmdutil.commitforceeditor() which forces tr.writepending()
   $ hg rebase --collapse --debug -b D -d Z | grep 'status stored'
   rebase status stored
   rebase status stored
@@ -162,12 +160,14 b' rebase can then be continued'
   rebasing 1:112478962961 "B" (B)
   rebasing 3:26805aba1e60 "C" (C)
   rebasing 5:f585351a92f8 "D" (D tip)
+  transaction abort!
+  rollback completed
   abort: edit failed: false exited with status 1
   [255]
   $ hg tglog
   o  5: D
   |
-  | @  4: Z
+  | o  4: Z
   | |
   o |  3: C
   | |
@@ -178,9 +178,9 b' rebase can then be continued'
   o  0: A
   
   $ hg rebase --continue
-  already rebased 1:112478962961 "B" (B) as e9b22a392ce0
-  already rebased 3:26805aba1e60 "C" (C) as e9b22a392ce0
-  already rebased 5:f585351a92f8 "D" (D tip) as e9b22a392ce0
+  rebasing 1:112478962961 "B" (B)
+  rebasing 3:26805aba1e60 "C" (C)
+  rebasing 5:f585351a92f8 "D" (D tip)
   saved backup bundle to $TESTTMP/collapse-cancel-editor/.hg/strip-backup/112478962961-cb2a9b47-rebase.hg
   $ hg tglog
   o  3: Collapsed revision