changegroup: fix pulling to treemanifest repo from flat repo (issue5066)

In c0f11347b107 (changegroup: don't support versions 01 and 02 with
treemanifests, 2016-01-19), I stopped supporting use of cg1 and cg2
with treemanifest repos. What I had not considered was that it's
perfectly safe to pull *to* a treemanifest repo using any changegroup
version. As reported in issue5066, I therefore broke pull from old
repos into a treemanifest repo. It was not covered by the test case,
because that pulled from a local repo while enabling treemanifests,
which enabled treemanifests on the source repo as well. After
switching to pulling via HTTP, it breaks.

Fix by splitting up changegroup.supportedversions() into
supportedincomingversions() and supportedoutgoingversions().

mercurial/bundle2.py

@@ -1242,7 +1242,8 b' def getrepocaps(repo, allowpushback=Fals'
     Exists to allow extensions (like evolution) to mutate the capabilities.
     """
     caps = capabilities.copy()
-    caps['changegroup'] = tuple(sorted(changegroup.supportedversions(repo)))
+    caps['changegroup'] = tuple(sorted(
+        changegroup.supportedincomingversions(repo)))
     if obsolete.isenabled(repo, obsolete.exchangeopt):
         supportedformat = tuple('V%i' % v for v in obsolete.formats)
         caps['obsmarkers'] = supportedformat

mercurial/bundlerepo.py

@@ -282,7 +282,7 b' class bundlerepository(localrepo.localre'
                                                   "multiple changegroups")
                     cgstream = part
                     version = part.params.get('version', '01')
-                    if version not in changegroup.supportedversions(self):
+                    if version not in changegroup.allsupportedversions(ui):
                         msg = _('Unsupported changegroup version: %s')
                         raise error.Abort(msg % version)
                     if self.bundle.compressed():

mercurial/changegroup.py

@@ -949,10 +949,25 b' class cg3packer(cg2packer):'
              '03': (cg3packer, cg3unpacker),
 }
 
-def supportedversions(repo):
+def allsupportedversions(ui):
     versions = set(_packermap.keys())
-    if ('treemanifest' in repo.requirements or
-        repo.ui.configbool('experimental', 'treemanifest')):
+    versions.discard('03')
+    if (ui.configbool('experimental', 'changegroup3') or
+        ui.configbool('experimental', 'treemanifest')):
+        versions.add('03')
+    return versions
+
+# Changegroup versions that can be applied to the repo
+def supportedincomingversions(repo):
+    versions = allsupportedversions(repo.ui)
+    if 'treemanifest' in repo.requirements:
+        versions.add('03')
+    return versions
+
+# Changegroup versions that can be created from the repo
+def supportedoutgoingversions(repo):
+    versions = allsupportedversions(repo.ui)
+    if 'treemanifest' in repo.requirements:
         # Versions 01 and 02 support only flat manifests and it's just too
         # expensive to convert between the flat manifest and tree manifest on
         # the fly. Since tree manifests are hashed differently, all of history
@@ -960,22 +975,21 b' def supportedversions(repo):'
         # support versions 01 and 02.
         versions.discard('01')
         versions.discard('02')
-    elif not repo.ui.configbool('experimental', 'changegroup3'):
-        versions.discard('03')
+        versions.add('03')
     return versions
 
 def safeversion(repo):
     # Finds the smallest version that it's safe to assume clients of the repo
     # will support. For example, all hg versions that support generaldelta also
     # support changegroup 02.
-    versions = supportedversions(repo)
+    versions = supportedoutgoingversions(repo)
     if 'generaldelta' in repo.requirements:
         versions.discard('01')
     assert versions
     return min(versions)
 
 def getbundler(version, repo, bundlecaps=None):
-    assert version in supportedversions(repo)
+    assert version in supportedoutgoingversions(repo)
     return _packermap[version][0](repo, bundlecaps)
 
 def getunbundler(version, fh, alg):

mercurial/exchange.py

@@ -707,7 +707,8 b' def _pushb2ctx(pushop, bundler):'
                                                 pushop.outgoing)
     else:
         cgversions = [v for v in cgversions
-                      if v in changegroup.supportedversions(pushop.repo)]
+                      if v in changegroup.supportedoutgoingversions(
+                          pushop.repo)]
         if not cgversions:
             raise ValueError(_('no common changegroup version'))
         version = max(cgversions)
@@ -1562,7 +1563,7 b' def _getbundlechangegrouppart(bundler, r'
         getcgkwargs = {}
         if cgversions:  # 3.1 and 3.2 ship with an empty value
             cgversions = [v for v in cgversions
-                          if v in changegroup.supportedversions(repo)]
+                          if v in changegroup.supportedoutgoingversions(repo)]
             if not cgversions:
                 raise ValueError(_('no common changegroup version'))
             version = getcgkwargs['version'] = max(cgversions)

tests/test-treemanifest.t

@@ -1,6 +1,8 b''
   $ cat << EOF >> $HGRCPATH
   > [format]
   > usegeneraldelta=yes
+  > [ui]
+  > ssh=python "$TESTDIR/dummyssh"
   > EOF
 
 Set up repo
@@ -203,15 +205,18 b' Create a few commits with flat manifest'
   (branch merge, don't forget to commit)
   $ hg ci -m 'merge of flat manifests to new flat manifest'
 
+  $ hg serve -p $HGPORT -d --pid-file=hg.pid --errorlog=errors.log
+  $ cat hg.pid >> $DAEMON_PIDS
+
 Create clone with tree manifests enabled
 
   $ cd ..
-  $ hg clone --pull --config experimental.treemanifest=1 repo-flat repo-mixed
-  requesting all changes
+  $ hg clone --config experimental.treemanifest=1 \
+  >   http://localhost:$HGPORT repo-mixed -r 1
   adding changesets
   adding manifests
   adding file changes
-  added 4 changesets with 17 changes to 11 files
+  added 2 changesets with 14 changes to 11 files
   updating to branch default
   11 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ cd repo-mixed
@@ -220,10 +225,20 b' Create clone with tree manifests enabled'
   $ grep treemanifest .hg/requires
   treemanifest
 
+Should be possible to push updates from flat to tree manifest repo
+
+  $ hg -R ../repo-flat push ssh://user@dummy/repo-mixed
+  pushing to ssh://user@dummy/repo-mixed
+  searching for changes
+  remote: adding changesets
+  remote: adding manifests
+  remote: adding file changes
+  remote: added 2 changesets with 3 changes to 3 files
+
 Commit should store revlog per directory
 
   $ hg co 1
-  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ echo 3 > a
   $ echo 3 > dir1/a
   $ echo 3 > dir1/dir1/a
@@ -456,13 +471,13 b' Add some more changes to the deep repo'
   $ hg ci -m troz
 
 Test cloning a treemanifest repo over http.
-  $ hg serve -p $HGPORT -d --pid-file=hg.pid --errorlog=errors.log
+  $ hg serve -p $HGPORT2 -d --pid-file=hg.pid --errorlog=errors.log
   $ cat hg.pid >> $DAEMON_PIDS
   $ cd ..
 We can clone even with the knob turned off and we'll get a treemanifest repo.
   $ hg clone --config experimental.treemanifest=False \
   >   --config experimental.changegroup3=True \
-  >   http://localhost:$HGPORT deepclone
+  >   http://localhost:$HGPORT2 deepclone
   requesting all changes
   adding changesets
   adding manifests