icasefs: rewrite case-folding collision detection (issue3452)
Before this patch, case-folding collision detection uses
"copies.pathcopies()" before "manifestmerge()", and is not aware of
renaming in some cases.
For example, in the case of issue3452, "copies.pathcopies()" can't
detect renaming, if the file is renamed at the revision before common
ancestor of merging. So, "hg merge" is aborted unexpectedly on case
insensitive filesystem.
This patch fully rewrites case-folding collision detection, and
relocate it into "manifestmerge()".
New implementation uses list of actions held in "actions" and
"prompts" to build provisional merged manifest up.
Provisional merged manifest should be correct, if actions required to
build merge result up in working directory are listed up in "actions"
and "prompts" correctly.
This patch checks case-folding collision still before prompting for
merge, to avoid aborting after some interactions with users. So, this
assumes that user would choose not "deleted" but "changed".
This patch also changes existing abort message, because sorting before
collision detection changes order of checked files.
# dicthelpers.py - helper routines for Python dicts
#
# Copyright 2013 Facebook
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
def diff(d1, d2, default=None):
'''Return all key-value pairs that are different between d1 and d2.
This includes keys that are present in one dict but not the other, and
keys whose values are different. The return value is a dict with values
being pairs of values from d1 and d2 respectively, and missing values
treated as default, so if a value is missing from one dict and the same as
default in the other, it will not be returned.'''
res = {}
if d1 is d2:
# same dict, so diff is empty
return res
for k1, v1 in d1.iteritems():
v2 = d2.get(k1, default)
if v1 != v2:
res[k1] = (v1, v2)
for k2 in d2:
if k2 not in d1:
v2 = d2[k2]
if v2 != default:
res[k2] = (default, v2)
return res
def join(d1, d2, default=None):
'''Return all key-value pairs from both d1 and d2.
This is akin to an outer join in relational algebra. The return value is a
dict with values being pairs of values from d1 and d2 respectively, and
missing values represented as default.'''
res = {}
for k1, v1 in d1.iteritems():
if k1 in d2:
res[k1] = (v1, d2[k1])
else:
res[k1] = (v1, default)
if d1 is d2:
return res
for k2 in d2:
if k2 not in d1:
res[k2] = (default, d2[k2])
return res