contrib/packagelib.sh

unamend: move fb extension unamend to core

unamend extension adds an unamend command which undoes the effect of the amend
command. This patch moves the unamend command from that extension to uncommit
extension and this one does not completely undoes the effect of amend command as
it creates a new commit, rather than reviving the old one back.

This also adds tests for the same.

.. feature::

   A new unamend command in uncommit extension which undoes the effect of the
   amend command by creating a new changeset which was there before amend and
   moving the changes that were amended to the working directory.

Differential Revision: https://phab.mercurial-scm.org/D821

# 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() {
    export HGRCPATH=
    export HGPLAIN=

    make cleanbutpackages
    make local PURE=--pure
    HG="$PWD/hg"

    "$HG" version > /dev/null || { echo 'abort: hg version failed!'; exit 1 ; }

    hgversion=`LANGUAGE=C "$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
}