contrib/builddeb

changelog: specify checkambig=True to revlog.__init__, to avoid ambiguity

If steps below occurs at "the same time in sec", all of mtime, ctime
and size are same between (1) and (3).

  1. append data to 00changelog.i (and close transaction)
  2. discard appended data by truncation (strip or rollback)
  3. append same size but different data to 00changelog.i again

Therefore, cache validation doesn't work after (3) as expected.

To avoid such file stat ambiguity around truncation, this patch
specifies checkambig=True to revlog.__init__(). This makes revlog
write changes out with checkambig=True.

Even though changes of 00changelog.i themselves are written out at
changelog._finalize(), this checkambig=True is needed, because
revlog.checkinlinesize(), which is invoked at the end of
changelog._finalize(), might replace already changed 00changelog.i by
converted one.

Even after this patch, avoiding file stat ambiguity of 00changelog.i
around truncation isn't yet completed, because truncation side isn't
aware of this issue.

This is a part of ExactCacheValidationPlan.

    https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan

#!/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
DISTID=`(lsb_release -is 2> /dev/null | tr '[:upper:]' '[:lower:]') || echo debian`
CODENAME=`lsb_release -cs 2> /dev/null || echo unknown`
DEBFLAGS=-b
while [ "$1" ]; do
    case "$1" in
    --distid )
        shift
        DISTID="$1"
        shift
        ;;
    --codename )
        shift
        CODENAME="$1"
        shift
        ;;
    --cleanup )
        shift
        BUILD=
        ;;
    --build )
        shift
        CLEANUP=
        ;;
    --source-only )
        shift
        DEBFLAGS=-S
        ;;
    * )
        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+$distance-$CODENAME-$node"
elif [ "$DEBFLAGS" = "-S" ] ; then
    # for building a ppa (--source-only) for a release (distance == 0), we need
    # to version the distroseries so that we can upload to launchpad
    debver="$debver~${CODENAME}1"
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

    sed -i.tmp "s/__VERSION__/$debver/" $changelog
    sed -i.tmp "s/__DATE__/$(date --rfc-2822)/" $changelog
    sed -i.tmp "s/__CODENAME__/$CODENAME/" $changelog
    rm $changelog.tmp

    # remove the node from the version string
    SRCFILE="mercurial_$(echo $debver | sed "s,-$node,,").orig.tar.gz"
    "$PWD/hg" archive $SRCFILE
    mv $SRCFILE ..
    debuild -us -uc -i -I $DEBFLAGS
    if [ $? != 0 ]; then
        echo 'debuild failed!'
        exit 1
    fi

fi
if [ "$CLEANUP" ] ; then
    echo
    OUTPUTDIR=${OUTPUTDIR:=packages/$DISTID-$CODENAME}
    mkdir -p "$OUTPUTDIR"
    find ../mercurial*.deb ../mercurial_*.build ../mercurial_*.changes \
          ../mercurial*.dsc ../mercurial*.gz \
          -type f -newer $control -print0 2>/dev/null | \
      xargs -Inarf -0 mv narf "$OUTPUTDIR"
    echo "Built packages for $debver:"
    find "$OUTPUTDIR" -type f -newer $control -name '*.deb'
fi