deltaparent(): don't return nullrev for a revision containing a full snapshot this allows us to simplify manifest.readdelta and revlog.revdiff

merge with stable

tests: fix up bisect test output

merge: move reverse-merge logic out of filemerge (issue2342)

bisect: add test for unrelated starting revisions

merge with stable

bisect: better message for unrelated starting revisions

debuginstall: report installpath

tests: unify test-glog

bookmarks: fix long line

merge with stable

revlog: addgroup re-adds punched revisions for missing parents While reading changegroup if a node with missing parents is encountered, we add a punched entry in the index with null parents for the missing parent node.