contrib/builddeb

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.

#!/bin/sh -e
#
# Build a Mercurial debian package from the current repo
#
# Tested on Jessie (stable as of original script authoring.)

. $(dirname $0)/packagelib.sh

BUILD=1
CLEANUP=1
DEBVERSION=jessie
while [ "$1" ]; do
    case "$1" in
    --release )
        shift
        DEBVERSION="$1"
        shift
        ;;
    --cleanup )
        shift
        BUILD=
        ;;
    --build )
        shift
        CLEANUP=
        ;;
    --debbuilddir )
        shift
        DEBBUILDDIR="$1"
        shift
        ;;
    * )
        echo "Invalid parameter $1!" 1>&2
        exit 1
        ;;
    esac
done

trap "if [ '$CLEANUP' ] ; then rm -r '$PWD/debian' ; fi" EXIT

set -u

if [ ! -d .hg ]; then
    echo 'You are not inside a Mercurial repository!' 1>&2
    exit 1
fi

gethgversion
debver="$version"
if [ -n "$type" ] ; then
    debver="$debver~$type"
fi
if [ -n "$distance" ] ; then
    debver="$debver+$distance-$node"
fi

control=debian/control
changelog=debian/changelog

if [ "$BUILD" ]; then
    if [ -d debian ] ; then
        echo "Error! debian control directory already exists!"
        exit 1
    fi

    cp -r $PWD/contrib/debian debian
    chmod -R 0755 debian

    # This looks like sed -i, but sed -i behaves just differently enough
    # between BSD and GNU sed that I gave up and did the dumb thing.
    sed "s/__VERSION__/$debver/" < $changelog > $changelog.tmp
    date=$(date --rfc-2822)
    sed "s/__DATE__/$date/" < $changelog.tmp > $changelog
    rm $changelog.tmp

    debuild -us -uc -b
    if [ $? != 0 ]; then
        echo 'debuild failed!'
        exit 1
    fi

fi
if [ "$CLEANUP" ] ; then
    echo
    OUTPUTDIR=${OUTPUTDIR:=packages/debian-$DEBVERSION}
    find ../mercurial*.deb ../mercurial_*.build ../mercurial_*.changes \
          -type f -newer $control -print0 | \
      xargs -Inarf -0 mv narf "$OUTPUTDIR"
    echo "Built packages for $debver:"
    find "$OUTPUTDIR" -type f -newer $control -name '*.deb'
fi