phabricator: use parents.set to always set dependencies

Now that Mercurial's Phabricator instance has been updated to a version that
supports the parents.set transaction on revision.edit we can use that to set
dependency relationships in patch stacks instead of abusing the summary.
This has the advantage that we can use it on every `phabsend` so commit
reordering is picked up without spamming changes like abusing the summary would,
and using parents.set will clear previous parents unlike parents.add.

Differential Revision: https://phab.mercurial-scm.org/D6514

hgext/phabricator.py

@@ -431,12 +431,13 b' def writediffproperties(ctx, diff):'
     }
     callconduit(ctx.repo().ui, b'differential.setdiffproperty', params)
 
-def createdifferentialrevision(ctx, revid=None, parentrevid=None, oldnode=None,
-                               olddiff=None, actions=None, comment=None):
+def createdifferentialrevision(ctx, revid=None, parentrevphid=None,
+                               oldnode=None, olddiff=None, actions=None,
+                               comment=None):
     """create or update a Differential Revision
 
     If revid is None, create a new Differential Revision, otherwise update
-    revid. If parentrevid is not None, set it as a dependency.
+    revid. If parentrevphid is not None, set it as a dependency.
 
     If oldnode is not None, check if the patch content (without commit message
     and metadata) has changed before creating another diff.
@@ -465,14 +466,10 b' def createdifferentialrevision(ctx, revi'
         diff = olddiff
     writediffproperties(ctx, diff)
 
-    # Use a temporary summary to set dependency. There might be better ways but
-    # I cannot find them for now. But do not do that if we are updating an
-    # existing revision (revid is not None) since that introduces visible
-    # churns (someone edited "Summary" twice) on the web page.
-    if parentrevid and revid is None:
-        summary = b'Depends on D%d' % parentrevid
-        transactions += [{b'type': b'summary', b'value': summary},
-                         {b'type': b'summary', b'value': b' '}]
+    # Set the parent Revision every time, so commit re-ordering is picked-up
+    if parentrevphid:
+        transactions.append({b'type': b'parents.set',
+                             b'value': [parentrevphid]})
 
     if actions:
         transactions += actions
@@ -583,9 +580,9 b' def phabsend(ui, repo, *revs, **opts):'
     drevids = [] # [int]
     diffmap = {} # {newnode: diff}
 
-    # Send patches one by one so we know their Differential Revision IDs and
+    # Send patches one by one so we know their Differential Revision PHIDs and
     # can provide dependency relationship
-    lastrevid = None
+    lastrevphid = None
     for rev in revs:
         ui.debug(b'sending rev %d\n' % rev)
         ctx = repo[rev]
@@ -595,10 +592,11 b' def phabsend(ui, repo, *revs, **opts):'
         if oldnode != ctx.node() or opts.get(b'amend'):
             # Create or update Differential Revision
             revision, diff = createdifferentialrevision(
-                ctx, revid, lastrevid, oldnode, olddiff, actions,
+                ctx, revid, lastrevphid, oldnode, olddiff, actions,
                 opts.get(b'comment'))
             diffmap[ctx.node()] = diff
             newrevid = int(revision[b'object'][b'id'])
+            newrevphid = revision[b'object'][b'phid']
             if revid:
                 action = b'updated'
             else:
@@ -612,8 +610,9 b' def phabsend(ui, repo, *revs, **opts):'
                 tags.tag(repo, tagname, ctx.node(), message=None, user=None,
                          date=None, local=True)
         else:
-            # Nothing changed. But still set "newrevid" so the next revision
-            # could depend on this one.
+            # Nothing changed. But still set "newrevphid" so the next revision
+            # could depend on this one and "newrevid" for the summary line.
+            newrevphid = querydrev(repo, str(revid))[0][b'phid']
             newrevid = revid
             action = b'skipped'
 
@@ -628,7 +627,7 b' def phabsend(ui, repo, *revs, **opts):'
         ui.write(_(b'%s - %s - %s: %s\n') % (drevdesc, actiondesc, nodedesc,
                                              desc))
         drevids.append(newrevid)
-        lastrevid = newrevid
+        lastrevphid = newrevphid
 
     # Update commit messages and remove tags
     if opts.get(b'amend'):

tests/phabricator/phabsend-create-public.json

@@ -700,7 +700,7 b''
                         "phab.mercurial-scm.org"
                     ]
                 },
-                "body": "api.token=cli-hahayouwish&transactions%5B0%5D%5Btype%5D=update&transactions%5B0%5D%5Bvalue%5D=PHID-DIFF-4pugk2zedyh2xm27uuvh&transactions%5B1%5D%5Btype%5D=summary&transactions%5B1%5D%5Bvalue%5D=Depends+on+D1192&transactions%5B2%5D%5Btype%5D=summary&transactions%5B2%5D%5Bvalue%5D=+&transactions%5B3%5D%5Btype%5D=title&transactions%5B3%5D%5Bvalue%5D=create+draft+change+for+phabricator+testing",
+                "body": "api.token=cli-hahayouwish&transactions%5B0%5D%5Btype%5D=update&transactions%5B0%5D%5Bvalue%5D=PHID-DIFF-4pugk2zedyh2xm27uuvh&transactions%5B1%5D%5Btype%5D=parents.set&transactions%5B1%5D%5Bvalue%5D%5B0%5D=PHID-DREV-qb4xy3abx7eu4puizvjl&transactions%5B2%5D%5Btype%5D=title&transactions%5B2%5D%5Bvalue%5D=create+draft+change+for+phabricator+testing",
                 "uri": "https://phab.mercurial-scm.org//api/differential.revision.edit",
                 "method": "POST"
             },

tests/phabricator/phabsend-update-alpha-create-beta.json

@@ -768,7 +768,7 b''
                         "phab.mercurial-scm.org"
                     ]
                 },
-                "body": "api.token=cli-hahayouwish&transactions%5B0%5D%5Btype%5D=update&transactions%5B0%5D%5Bvalue%5D=PHID-DIFF-uhbyhoejzbniwwzj2q5c&transactions%5B1%5D%5Btype%5D=summary&transactions%5B1%5D%5Bvalue%5D=Depends+on+D1190&transactions%5B2%5D%5Btype%5D=summary&transactions%5B2%5D%5Bvalue%5D=+&transactions%5B3%5D%5Btype%5D=title&transactions%5B3%5D%5Bvalue%5D=create+beta+for+phabricator+test",
+                "body": "api.token=cli-hahayouwish&transactions%5B0%5D%5Btype%5D=update&transactions%5B0%5D%5Bvalue%5D=PHID-DIFF-uhbyhoejzbniwwzj2q5c&transactions%5B1%5D%5Btype%5D=parents.set&transactions%5B1%5D%5Bvalue%5D%5B0%5D=PHID-DREV-kikesmfxhzpfaxbzgj3l&transactions%5B2%5D%5Btype%5D=title&transactions%5B2%5D%5Bvalue%5D=create+beta+for+phabricator+test",
                 "uri": "https://phab.mercurial-scm.org//api/differential.revision.edit",
                 "method": "POST"
             },