phase: add a dedicated pretxnclose-phase hook

This new hook mirror the newly introduced 'txnclose-phase' but can abort the
transaction.

mercurial/help/config.txt

@@ -1002,6 +1002,17 b' be ``$HG_HOOKTYPE=incoming`` and ``$HG_H'
   ``$HG_TXNNAME``, and a unique identifier for the transaction will be in
   ``HG_TXNID``.
 
+``pretxnclose-phase``
+  Run right before a phase change is actually finalized. Any repository change
+  will be visible to the hook program. This lets you validate the transaction
+  content or change it. Exit status 0 allows the commit to proceed.  A non-zero
+  status will cause the transaction to be rolled back.
+  The affected node is available in ``$HG_NODE``, the phase in ``$HG_PHASE``
+  while the previous ``$HG_OLDPHASE``. In case of new node, ``$HG_OLDPHASE``
+  will be empty.  In addition, the reason for the transaction opening will be in
+  ``$HG_TXNNAME``, and a unique identifier for the transaction will be in
+  ``HG_TXNID``.
+
 ``txnclose``
   Run after any repository transaction has been committed. At this
   point, the transaction can no longer be rolled back. The hook will run
@@ -1017,12 +1028,8 b' be ``$HG_HOOKTYPE=incoming`` and ``$HG_H'
 ``txnclose-phase``
   Run after any phase change has been committed. At this point, the
   transaction can no longer be rolled back. The hook will run after the lock
-  is released.
-  The affected node is available in ``$HG_NODE``, the new phase will be
-  available in ``$HG_PHASE`` while the previous phase will be available in
-  ``$HG_OLDPHASE``. In case of new node, ``$HG_OLDPHASE`` will be empty.  In
-  addition, the reason for the transaction opening will be in ``$HG_TXNNAME``,
-  and a unique identifier for the transaction will be in ``HG_TXNID``.
+  is released. See :hg:`help config.hooks.pretxnclose-phase` for details about
+  available variables.
 
 ``txnabort``
   Run when a transaction is aborted. See :hg:`help config.hooks.pretxnclose`

mercurial/localrepo.py

@@ -1243,6 +1243,14 b' class localrepository(object):'
                     repo.hook('pretxnclose-bookmark', throw=True,
                               txnname=desc,
                               **pycompat.strkwargs(args))
+            if hook.hashook(repo.ui, 'pretxnclose-phase'):
+                cl = repo.unfiltered().changelog
+                for rev, (old, new) in tr.changes['phases'].items():
+                    args = tr.hookargs.copy()
+                    node = hex(cl.node(rev))
+                    args.update(phases.preparehookargs(node, old, new))
+                    repo.hook('pretxnclose-phase', throw=True, txnname=desc,
+                              **pycompat.strkwargs(args))
 
             repo.hook('pretxnclose', throw=True,
                       txnname=desc, **pycompat.strkwargs(tr.hookargs))

tests/test-phases.t

@@ -732,3 +732,94 b' repositories visible to an external hook'
   rollback completed
   abort: pretxnclose hook exited with status 1
   [255]
+
+Check that pretxnclose-phase hook can control phase movement
+
+  $ hg phase --force b3325c91a4d9 --secret
+  test-debug-phase: move rev 3: 0 -> 2
+  test-debug-phase: move rev 4: 0 -> 2
+  test-debug-phase: move rev 5: 1 -> 2
+  test-debug-phase: move rev 7: 0 -> 2
+  test-hook-close-phase: b3325c91a4d916bcc4cdc83ea3fe4ece46a42f6e:  0 -> 2
+  test-hook-close-phase: a603bfb5a83e312131cebcd05353c217d4d21dde:  0 -> 2
+  test-hook-close-phase: a030c6be5127abc010fcbff1851536552e6951a8:  1 -> 2
+  test-hook-close-phase: 17a481b3bccb796c0521ae97903d81c52bfee4af:  0 -> 2
+  $ hg log -G -T phases
+  @    changeset:   7:17a481b3bccb
+  |\   tag:         tip
+  | |  phase:       secret
+  | |  parent:      6:cf9fe039dfd6
+  | |  parent:      4:a603bfb5a83e
+  | |  user:        test
+  | |  date:        Thu Jan 01 00:00:00 1970 +0000
+  | |  summary:     merge B' and E
+  | |
+  | o  changeset:   6:cf9fe039dfd6
+  | |  phase:       public
+  | |  parent:      1:27547f69f254
+  | |  user:        test
+  | |  date:        Thu Jan 01 00:00:00 1970 +0000
+  | |  summary:     B'
+  | |
+  o |  changeset:   4:a603bfb5a83e
+  | |  phase:       secret
+  | |  user:        test
+  | |  date:        Thu Jan 01 00:00:00 1970 +0000
+  | |  summary:     E
+  | |
+  o |  changeset:   3:b3325c91a4d9
+  | |  phase:       secret
+  | |  user:        test
+  | |  date:        Thu Jan 01 00:00:00 1970 +0000
+  | |  summary:     D
+  | |
+  o |  changeset:   2:f838bfaca5c7
+  |/   phase:       public
+  |    user:        test
+  |    date:        Thu Jan 01 00:00:00 1970 +0000
+  |    summary:     C
+  |
+  o  changeset:   1:27547f69f254
+  |  phase:       public
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     B
+  |
+  o  changeset:   0:4a2df7238c3b
+     phase:       public
+     user:        test
+     date:        Thu Jan 01 00:00:00 1970 +0000
+     summary:     A
+  
+
+Install a hook that prevent b3325c91a4d9 to become public
+
+  $ cat >> .hg/hgrc << EOF
+  > [hooks]
+  > pretxnclose-phase.nopublish_D = (echo \$HG_NODE| grep -v b3325c91a4d9>/dev/null) || [ 0 -lt \$HG_PHASE ]
+  > EOF
+
+Try various actions. only the draft move should succeed
+
+  $ hg phase --public b3325c91a4d9
+  transaction abort!
+  rollback completed
+  abort: pretxnclose-phase.nopublish_D hook exited with status 1
+  [255]
+  $ hg phase --public a603bfb5a83e
+  transaction abort!
+  rollback completed
+  abort: pretxnclose-phase.nopublish_D hook exited with status 1
+  [255]
+  $ hg phase --draft 17a481b3bccb
+  test-debug-phase: move rev 3: 2 -> 1
+  test-debug-phase: move rev 4: 2 -> 1
+  test-debug-phase: move rev 7: 2 -> 1
+  test-hook-close-phase: b3325c91a4d916bcc4cdc83ea3fe4ece46a42f6e:  2 -> 1
+  test-hook-close-phase: a603bfb5a83e312131cebcd05353c217d4d21dde:  2 -> 1
+  test-hook-close-phase: 17a481b3bccb796c0521ae97903d81c52bfee4af:  2 -> 1
+  $ hg phase --public 17a481b3bccb
+  transaction abort!
+  rollback completed
+  abort: pretxnclose-phase.nopublish_D hook exited with status 1
+  [255]