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.
# Extract version number into 4 parts, some of which may be empty:
#
# version: the numeric part of the most recent tag. Will always look like 1.3.
#
# type: if an rc build, "rc", otherwise empty
#
# distance: the distance from the nearest tag, or empty if built from a tag
#
# node: the node|short hg was built from, or empty if built from a tag
gethgversion() {
make clean
make local || make local PURE=--pure
HG="$PWD/hg"
$HG version > /dev/null || { echo 'abort: hg version failed!'; exit 1 ; }
hgversion=`$HG version | sed -ne 's/.*(version \(.*\))$/\1/p'`
if echo $hgversion | grep + > /dev/null 2>&1 ; then
tmp=`echo $hgversion | cut -d+ -f 2`
hgversion=`echo $hgversion | cut -d+ -f 1`
distance=`echo $tmp | cut -d- -f 1`
node=`echo $tmp | cut -d- -f 2`
else
distance=''
node=''
fi
if echo $hgversion | grep -- '-' > /dev/null 2>&1; then
version=`echo $hgversion | cut -d- -f1`
type=`echo $hgversion | cut -d- -f2`
else
version=$hgversion
type=''
fi
}