convert: keep branch switching merges with ancestors (
issue3340)
When running convert with a filemap, merge parents which are ancestors
of other parents are ignored. This is hardly a problem when parents
belong to the same branch, but the result could be confusing when named
branches are involved. With:
-o-a1-a2-a3... <- A
\ \
b1-b2-b3...-m- <- B
If all b* revisions are discarded, it is useful to preserve 'm' even if
it is empty after filtering to record the branch switch.
This patch makes filemap preserve "ancestor parents" if there is no
"non-ancestor parent" on the same branch than the merge revision.
Remarks:
- I am not completely convinced by the reasons given above and those
detailed by Matt in this thread:
http://selenic.com/pipermail/mercurial-devel/2012-May/040627.html
The properties we try to preserve are not clearly defined. That said,
I know this patch already helped someone on IRC and the tests output
look reasonable.
- This is a new version of the original "convert: filemap must preserve
fast-forward merges" patch. It has exactly the same output for 2
parents merges, the additional complexity is here to handle more than
two parents.
# node.py - basic nodeid manipulation for mercurial
#
# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
import binascii
nullrev = -1
nullid = "\0" * 20
# This ugly style has a noticeable effect in manifest parsing
hex = binascii.hexlify
bin = binascii.unhexlify
def short(node):
return hex(node[:6])