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.
# formatter.py - generic output formatting for mercurial
#
# Copyright 2012 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.
class baseformatter(object):
def __init__(self, ui, topic, opts):
self._ui = ui
self._topic = topic
self._style = opts.get("style")
self._template = opts.get("template")
self._item = None
def __bool__(self):
'''return False if we're not doing real templating so we can
skip extra work'''
return True
def _showitem(self):
'''show a formatted item once all data is collected'''
pass
def startitem(self):
'''begin an item in the format list'''
if self._item is not None:
self._showitem()
self._item = {}
def data(self, **data):
'''insert data into item that's not shown in default output'''
def write(self, fields, deftext, *fielddata, **opts):
'''do default text output while assigning data to item'''
for k, v in zip(fields.split(), fielddata):
self._item[k] = v
def plain(self, text, **opts):
'''show raw text for non-templated mode'''
pass
def end(self):
'''end output for the formatter'''
if self._item is not None:
self._showitem()
class plainformatter(baseformatter):
'''the default text output scheme'''
def __init__(self, ui, topic, opts):
baseformatter.__init__(self, ui, topic, opts)
def __bool__(self):
return False
def startitem(self):
pass
def data(self, **data):
pass
def write(self, fields, deftext, *fielddata, **opts):
self._ui.write(deftext % fielddata, **opts)
def plain(self, text, **opts):
self._ui.write(text, **opts)
def end(self):
pass
class debugformatter(baseformatter):
def __init__(self, ui, topic, opts):
baseformatter.__init__(self, ui, topic, opts)
self._ui.write("%s = {\n" % self._topic)
def _showitem(self):
self._ui.write(" " + repr(self._item) + ",\n")
def end(self):
baseformatter.end(self)
self._ui.write("}\n")
def formatter(ui, topic, opts):
if ui.configbool('ui', 'formatdebug'):
return debugformatter(ui, topic, opts)
return plainformatter(ui, topic, opts)