buildrpm: use bash shebang, since we use bash features in the script

As suggested by Bryan O'Sullivan.

contrib/buildrpm

@@ -1,161 +1,161 b''
-#!/bin/sh -e
+#!/bin/bash -e
 #
 # Build a Mercurial RPM from the current repo
 #
 # Tested on
 # - Fedora 20
 # - CentOS 5
 # - centOS 6
 
 . $(dirname $0)/packagelib.sh
 
 BUILD=1
 RPMBUILDDIR="$PWD/rpmbuild"
 while [ "$1" ]; do
     case "$1" in
     --prepare )
         shift
         BUILD=
         ;;
     --withpython | --with-python)
         shift
         PYTHONVER=2.7.10
         PYTHONMD5=d7547558fd673bd9d38e2108c6b42521
         ;;
     --rpmbuilddir )
         shift
         RPMBUILDDIR="$1"
         shift
         ;;
     * )
         echo "Invalid parameter $1!" 1>&2
         exit 1
         ;;
     esac
 done
 
 cd "`dirname $0`/.."
 
 specfile=$PWD/contrib/mercurial.spec
 if [ ! -f $specfile ]; then
     echo "Cannot find $specfile!" 1>&2
     exit 1
 fi
 
 if [ ! -d .hg ]; then
     echo 'You are not inside a Mercurial repository!' 1>&2
     exit 1
 fi
 
 gethgversion
 
 # TODO: handle distance/node set, and type set
 
 if [ -z "$type" ] ; then
    release=1
 else
     release=0.9_$type
 fi
 
 if [ -n "$distance" ] ; then
     release=$release+$distance_$node
 fi
 
 if [ "$PYTHONVER" ]; then
     release=$release+$PYTHONVER
     RPMPYTHONVER=$PYTHONVER
 else
     RPMPYTHONVER=%{nil}
 fi
 
 mkdir -p $RPMBUILDDIR/{SOURCES,BUILD,SRPMS,RPMS}
 $HG archive -t tgz $RPMBUILDDIR/SOURCES/mercurial-$version-$release.tar.gz
 if [ "$PYTHONVER" ]; then
 (
     mkdir -p build
     cd build
     PYTHON_SRCFILE=Python-$PYTHONVER.tgz
     [ -f $PYTHON_SRCFILE ] || curl -Lo $PYTHON_SRCFILE http://www.python.org/ftp/python/$PYTHONVER/$PYTHON_SRCFILE
     if [ "$PYTHONMD5" ]; then
         echo "$PYTHONMD5 $PYTHON_SRCFILE" | md5sum -w -c
     fi
     ln -f $PYTHON_SRCFILE $RPMBUILDDIR/SOURCES/$PYTHON_SRCFILE
 
     DOCUTILSVER=`sed -ne "s/^%global docutilsname docutils-//p" $specfile`
     DOCUTILS_SRCFILE=docutils-$DOCUTILSVER.tar.gz
     [ -f $DOCUTILS_SRCFILE ] || curl -Lo $DOCUTILS_SRCFILE http://downloads.sourceforge.net/project/docutils/docutils/$DOCUTILSVER/$DOCUTILS_SRCFILE
     DOCUTILSMD5=`sed -ne "s/^%global docutilsmd5 //p" $specfile`
     if [ "$DOCUTILSMD5" ]; then
         echo "$DOCUTILSMD5 $DOCUTILS_SRCFILE" | md5sum -w -c
     fi
     ln -f $DOCUTILS_SRCFILE $RPMBUILDDIR/SOURCES/$DOCUTILS_SRCFILE
 )
 fi
 
 mkdir -p $RPMBUILDDIR/SPECS
 rpmspec=$RPMBUILDDIR/SPECS/mercurial.spec
 
 sed -e "s,^Version:.*,Version: $version," \
     -e "s,^Release:.*,Release: $release," \
     $specfile > $rpmspec
 
 echo >> $rpmspec
 echo "%changelog" >> $rpmspec
 
 if echo $version | grep '+' > /dev/null 2>&1; then
     latesttag="`echo $version | sed -e 's/+.*//'`"
     $HG log -r .:"$latesttag" -fM \
         --template '{date|hgdate}\t{author}\t{desc|firstline}\n' | python -c '
 import sys, time
 
 def datestr(date, format):
     return time.strftime(format, time.gmtime(float(date[0]) - date[1]))
 
 changelog = []
 for l in sys.stdin.readlines():
     tok = l.split("\t")
     hgdate = tuple(int(v) for v in tok[0].split())
     changelog.append((datestr(hgdate, "%F"), tok[1], hgdate, tok[2]))
 prevtitle = ""
 for l in sorted(changelog, reverse=True):
     title = "* %s %s" % (datestr(l[2], "%a %b %d %Y"), l[1])
     if prevtitle != title:
         prevtitle = title
         print
         print title
     print "- %s" % l[3].strip()
 ' >> $rpmspec
 
 else
 
     $HG log \
          --template '{date|hgdate}\t{author}\t{desc|firstline}\n' \
          .hgtags | python -c '
 import sys, time
 
 def datestr(date, format):
     return time.strftime(format, time.gmtime(float(date[0]) - date[1]))
 
 for l in sys.stdin.readlines():
     tok = l.split("\t")
     hgdate = tuple(int(v) for v in tok[0].split())
     print "* %s %s\n- %s" % (datestr(hgdate, "%a %b %d %Y"), tok[1], tok[2])
 ' >> $rpmspec
 
 fi
 
 sed -i \
     -e "s/^%define withpython.*$/%define withpython $RPMPYTHONVER/" \
     $rpmspec
 
 if [ "$BUILD" ]; then
     rpmbuild --define "_topdir $RPMBUILDDIR" -ba $rpmspec --clean
     if [ $? = 0 ]; then
         echo
         echo "Built packages for $version-$release:"
         find $RPMBUILDDIR/*RPMS/ -type f -newer $rpmspec
     fi
 else
     echo "Prepared sources for $version-$release $rpmspec are in $RPMBUILDDIR/SOURCES/ - use like:"
     echo "rpmbuild --define '_topdir $RPMBUILDDIR' -ba $rpmspec --clean"
 fi