[PATCH 10 of 15] Supports pull from httprepo. Pull works as below

[Pradeepkumar Gayam]

# HG changeset patch
# User Pradeepkumar Gayam <in3xes at gmail.com>
# Date 1278880556 -19800
# Branch stable
# Node ID 80e7ed5acc92171cc21c8d0bbced5c486ff5b0b0
# Parent  3c91a6fb7298312cea1f0cc0190393a6ad20a3cd
Supports pull from httprepo. Pull works as below

+--------------------------------------+
|            |  ld Client | New Client |
+------------+------------+------------+
| Old Server | Linear     | Linear [2] |
+------------+------------+------------+
| New Server | Linear [1] | Parent     |
+--------------------------------------+

[1] Server sends linear delta irrespective of the repo.
[2] Client adds linear deltas to the repository irrespective of client repo.

diff -r 3c91a6fb7298 -r 80e7ed5acc92 mercurial/hgweb/protocol.py
--- a/mercurial/hgweb/protocol.py	Mon Jul 12 01:40:03 2010 +0530
+++ b/mercurial/hgweb/protocol.py	Mon Jul 12 02:05:56 2010 +0530
@@ -21,7 +21,7 @@
 ]
 
 HGTYPE = 'application/mercurial-0.1'
-basecaps = 'lookup changegroupsubset branchmap pushkey'.split()
+basecaps = 'lookup changegroupsubset branchmap pushkey parentdelta'.split()
 
 def lookup(repo, req):
     try:
@@ -75,8 +75,9 @@
     if 'roots' in req.form:
         nodes = map(bin, req.form['roots'][0].split(" "))
 
+    pdelta = 'parentdelta' in req.form
     z = zlib.compressobj()
-    f = repo.changegroup(nodes, 'serve')
+    f = repo.changegroup(nodes, 'serve', pdelta)
     while 1:
         chunk = f.read(4096)
         if not chunk:
@@ -95,8 +96,9 @@
     if 'heads' in req.form:
         heads = [bin(x) for x in req.form['heads'][0].split(' ')]
 
+    pdelta = 'parentdelta' in req.form
     z = zlib.compressobj()
-    f = repo.changegroupsubset(bases, heads, 'serve')
+    f = repo.changegroupsubset(bases, heads, 'serve', pdelta=pdelta)
     while 1:
         chunk = f.read(4096)
         if not chunk:
diff -r 3c91a6fb7298 -r 80e7ed5acc92 mercurial/httprepo.py
--- a/mercurial/httprepo.py	Mon Jul 12 01:40:03 2010 +0530
+++ b/mercurial/httprepo.py	Mon Jul 12 02:05:56 2010 +0530
@@ -195,16 +195,23 @@
                 raise error.ResponseError(_("unexpected response:"), d)
         return r
 
-    def changegroup(self, nodes, kind):
+    def changegroup(self, nodes, kind, pdelta=False):
         n = " ".join(map(hex, nodes))
-        f = self.do_cmd("changegroup", roots=n)
+        if pdelta:
+            f = self.do_cmd("changegroup", roots=n, parentdelta="parentdelta")
+        else:
+            f = self.do_cmd("changegroup", roots=n)
         return util.chunkbuffer(zgenerator(f))
 
-    def changegroupsubset(self, bases, heads, source):
+    def changegroupsubset(self, bases, heads, source, pdelta=False):
         self.requirecap('changegroupsubset', _('look up remote changes'))
         baselst = " ".join([hex(n) for n in bases])
         headlst = " ".join([hex(n) for n in heads])
-        f = self.do_cmd("changegroupsubset", bases=baselst, heads=headlst)
+        if pdelta:
+            f = self.do_cmd("changegroupsubset", bases=baselst, heads=headlst,
+                            parentdelta="parentdelta")
+        else:
+            f = self.do_cmd("changegroupsubset", bases=baselst, heads=headlst)
         return util.chunkbuffer(zgenerator(f))
 
     def unbundle(self, cg, heads, source):
diff -r 3c91a6fb7298 -r 80e7ed5acc92 mercurial/localrepo.py
--- a/mercurial/localrepo.py	Mon Jul 12 01:40:03 2010 +0530
+++ b/mercurial/localrepo.py	Mon Jul 12 02:05:56 2010 +0530
@@ -1185,6 +1185,7 @@
             tmp = discovery.findcommonincoming(self, remote, heads=heads,
                                                force=force)
             common, fetch, rheads = tmp
+            pdelta = remote.capable('parentdelta')
             if not fetch:
                 self.ui.status(_("no changes found\n"))
                 return 0
@@ -1196,14 +1197,15 @@
                 heads = rheads
 
             if heads is None:
-                cg = remote.changegroup(fetch, 'pull')
+                cg = remote.changegroup(fetch, 'pull', pdelta)
             else:
                 if not remote.capable('changegroupsubset'):
                     raise util.Abort(_("Partial pull cannot be done because "
                                        "other repository doesn't support "
                                        "changegroupsubset."))
                 cg = remote.changegroupsubset(fetch, heads, 'pull')
-            return self.addchangegroup(cg, 'pull', remote.url(), lock=lock)
+            return self.addchangegroup(cg, 'pull', remote.url(), lock=lock,
+                                       pdelta=pdelta)
         finally:
             lock.release()