[PATCH 13 of 14] revlog: addgroup adds punched revisions for missing parents

[Vishakh H]

# HG changeset patch
# User Vishakh H <vsh426 at gmail.com>
# Date 1279263210 -19800
# Node ID d642d2f27fb25575d968ebee3870a2181a928a3e
# Parent  896eb69fd908e63b2f5b34593da168fc35f49661
revlog: addgroup adds punched revisions for missing parents

while reading changegroup if a node with missing parents is encountered,
we make a punched entry in the index with null parents for the parent node.

diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -1267,7 +1267,23 @@
 
                 for p in (p1, p2):
                     if not p in self.nodemap:
-                        raise LookupError(p, self.indexfile, _('unknown parent'))
+                        if self._shallow:
+                            if base == -1:
+                                base = len(self)
+                            e = (offset_type(end, REVLOG_PUNCHED_FLAG),
+                                 0, 0, base, nullrev, nullrev, nullrev, p)
+                            self.index.insert(-1, e)
+                            self.nodemap[p] = r
+                            entry = self._io.packentry(e, self.node,
+                                                       self.version, r)
+                            ifh.write(entry)
+                            t, r = r, r + 1
+                            base = self.base(t)
+                            start = self.start(base)
+                            end = self.end(t)
+                        else:
+                            raise LookupError(p, self.indexfile,
+                                              _('unknown parent'))
 
                 if not chain:
                     # retrieve the parent revision of the delta chain
@@ -1291,7 +1307,10 @@
                     if dfh:
                         dfh.flush()
                     ifh.flush()
-                    text = self.revision(chain)
+                    if self.flags(self.rev(chain), REVLOG_PUNCHED_FLAG):
+                        text = ""
+                    else:
+                        text = self.revision(chain)
                     if len(text) == 0:
                         # skip over trivial delta header
                         text = buffer(delta, 12)
@@ -1309,6 +1328,8 @@
                         raise RevlogError(_("consistency error adding group"))
                     textlen = len(text)
                 else:
+                    if base == -1:
+                        base = len(self)
                     e = (offset_type(end, 0), cdeltalen, textlen, base,
                          link, self.rev(p1), self.rev(p2), node)
                     self.index.insert(-1, e)