filectx: add isabsent method
This will indicate whether this filectx represents a file that is *not* in a
changectx. This will be used by merge and filemerge code to know about when a
conflict is a change/delete conflict.
While this is kind of hacky, it is the least bad of all the alternatives. Other
options considered but rejected include:
- isinstance(fctx, ...) -- not very Pythonic, doesn't support duck typing
- fctx.size() is None -- the 'size()' call on workingfilectxes causes a disk stat
- fctx.filenode() == nullid -- the semantics around filenode are incredibly
confusing. In particular, for workingfilectxes, filenode() is always None no
matter whether the file is present on disk or in either parent. Having different
behavior for None versus nullid in the merge code is just asking for pain.
Thanks to Pierre-Yves David for early review feedback here.
Format: http://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Name: mercurial
Source: http://www.selenic.com/mercurial/
Files: *
Copyright: 2005-2015, Matt Mackall <mpm@selenic.com> and others.
License: GPL-2+
This program is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later
version.
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This program is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the GNU General Public License for more
details.
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You should have received a copy of the GNU General Public
License along with this package; if not, write to the Free
Software Foundation, Inc., 51 Franklin St, Fifth Floor,
Boston, MA 02110-1301 USA
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On Debian systems, the full text of the GNU General Public
License version 2 can be found in the file
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