contrib/packagelib.sh

pathauditor: change parts verification order to be root first

Previously, when we verified the parts of a path in the auditor, we would
validate the deepest directory first, then it's parent, and so on up to the
root. If there happened to be a symlink in the chain, that meant our first check
would likely traverse that symlink.  In some cases that symlink might point to
a network filesystem that is expensive, and therefore this simple check could be
very slow.

The fix is to check the path parts starting at the root and working our way
down.

This has a minor performance difference in that we used to be able to short
circuit from the audit if we reached a directory that had already been checked.
Now we can't, but the cost is N dictionary look ups, where N is the number of
parts in the path, which should be fairly minor.

# 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
}