buildrpm: enhance changelog of the RPM file

Now the changelog is different depending if the parent is tagged:
- for tags, keep the previous content, i.e. changelog of the tags.
- for nightly build, changelog of the changesets since the latest tag

As RPM is expecting strictly descending dates, I have used a python
script to reorder the mercurial changelog.

contrib/buildrpm

@@ -1,78 +1,110
 #!/bin/sh
 #
 # Build a Mercurial RPM in place.
 #
 # Tested on
 # - Fedora 8 (with docutils 0.5)
 # - Fedora 11
 # - OpenSuse 11.2
 
 cd "`dirname $0`/.."
 HG="$PWD/hg"
 PYTHONPATH="$PWD/mercurial/pure"
 export PYTHONPATH
 
 specfile=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
 
 if $HG id -i | grep '+$' > /dev/null 2>&1; then
     echo -n "Your local changes will NOT be in the RPM. Continue [y/n] ? "
     read answer
     if echo $answer | grep -iv '^y'; then
         exit
     fi
 fi
 
 rpmdir="$PWD/rpmbuild"
 
 rm -rf $rpmdir
 mkdir -p $rpmdir/SOURCES $rpmdir/SPECS $rpmdir/RPMS $rpmdir/SRPMS $rpmdir/BUILD
 
 # 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
 
 $HG archive -t tgz $rpmdir/SOURCES/mercurial-$version.tar.gz
 rpmspec=$rpmdir/SPECS/mercurial-$version.spec
 
 sed -e "s,^Version:.*,Version: $version," \
     -e "s,^Release:.*,Release: $release," \
     $specfile > $rpmspec
 
-cat <<EOF >> $rpmspec
-%changelog
-* `LANG=en_US date +'%a %b %d %Y'` `$HG showconfig ui.username` $version-$release
-- Automatically built via $0
+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]))
 
-EOF
+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|rfc822date} {author}\n- {desc|firstline}\n\n' \
-     .hgtags \
-  | sed -e 's/^\(\* [MTWFS][a-z][a-z]\), \([0-3][0-9]\) \([A-Z][a-z][a-z]\) /\1 \3 \2 /' \
-        -e '/^\* [MTWFS][a-z][a-z] /{s/ [012][0-9]:[0-9][0-9]:[0-9][0-9] [+-][0-9]\{4\}//}' \
-   >> $rpmspec
+         --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
 
 rpmbuild --define "_topdir $rpmdir" -ba $rpmspec --clean
 if [ $? = 0 ]; then
     echo
     echo "Packages are in $rpmdir:"
     ls -l $rpmdir/*RPMS/*
 fi