sidedata: gate sidedata functionality to revlogv2 in more places

Since revlogv1 is not capable of storing sidedata, we prevent sidedata
mechanisms around the revlog layer from doing anything. We however keep the
ones that allow a revlogv1 repo to generate sidedata on-the-fly on a push, the
pull case simply does not add the sidedata to the revlog.

Differential Revision: https://phab.mercurial-scm.org/D10341

mercurial/changegroup.py

@@ -293,7 +293,12 b' class cg1unpacker(object):'
 
         # Only useful if we're adding sidedata categories. If both peers have
         # the same categories, then we simply don't do anything.
-        if self.version == b'04' and srctype == b'pull':
+        adding_sidedata = (
+            requirements.REVLOGV2_REQUIREMENT in repo.requirements
+            and self.version == b'04'
+            and srctype == b'pull'
+        )
+        if adding_sidedata:
             sidedata_helpers = get_sidedata_helpers(
                 repo,
                 sidedata_categories or set(),

mercurial/localrepo.py

@@ -3365,6 +3365,9 b' class localrepository(object):'
         return self.pathto(fp.name[len(self.root) + 1 :])
 
     def register_wanted_sidedata(self, category):
+        if requirementsmod.REVLOGV2_REQUIREMENT not in self.requirements:
+            # Only revlogv2 repos can want sidedata.
+            return
         self._wanted_sidedata.add(pycompat.bytestr(category))
 
     def register_sidedata_computer(self, kind, category, keys, computer):

mercurial/revlog.py

@@ -2246,7 +2246,7 b' class revlog(object):'
 
         deltainfo = deltacomputer.finddeltainfo(revinfo, fh)
 
-        if sidedata:
+        if sidedata and self.version & 0xFFFF == REVLOGV2:
             serialized_sidedata = sidedatautil.serialize_sidedata(sidedata)
             sidedata_offset = offset + deltainfo.deltalen
         else: