buildrpm: build from working dir parent and use hg version for RPM versioning

Previous, RPMs was always built from tip, and the release number did not match
the 'hg version' put in place for 1.4.
This will enable also to this script to be able to build official tag and not
only nightly build.

contrib/buildrpm

@@ -26,7 +26,7 b' rpmdir=/tmp/"`basename $root | sed \'s/ /'
 cd "$root"
 rm -rf $rpmdir
 mkdir -p $rpmdir/RPMS
-$HG clone "$root" $rpmdir/BUILD
+$HG clone -u . "$root" $rpmdir/BUILD
 
 if [ ! -f $specfile ]; then
     echo "Cannot find $specfile!" 1>&2
@@ -34,11 +34,19 b' if [ ! -f $specfile ]; then'
 fi
 
 tmpspec=/tmp/`basename "$specfile"`.$$ # FIXME: Insecure /tmp handling
-# Use the most recent tag as the version.
-version=`$HG tags | python -c 'import sys; print [l for l in sys.stdin.readlines() if l[0].isdigit()][0].split()[0]'`
-# Compute the release number as the difference in revision numbers
-# between the tip and the most recent tag.
-release=`$HG tags | python -c 'import sys; l = sys.stdin.readlines(); print int(l[0].split()[1].split(":")[0]) - int([x for x in l if x[0].isdigit()][0].split()[1].split(":")[0])'`
+# make setup.py build the version string
+python setup.py build_py -c -d .
+hgversion=`$HG version | sed -ne 's/.*(version \(.*\))$/\1/p'`
+
+if echo $hgversion | grep -- '-' > /dev/null 2>&1; then
+    # nightly build case, version is like 1.3.1+250-20b91f91f9ca
+    version=`echo $hgversion | cut -d- -f1`
+    release=`echo $hgversion | cut -d- -f2 | sed -e 's/+.*//'`
+else
+    # official tag, version is like 1.3.1
+    version=`echo $hgversion | sed -e 's/+.*//'`
+    release='0'
+fi
 tip=`$HG -q tip`
 
 # Beat up the spec file