SCRIPTS: improve announce-release to support different tag and versions

By having three variables it will be easier to preset the version and
the tag separately. One contains the announced version, another one the
associated tag and the last one the final commit ID (used as the ending
point before the release). This initially allows to check for the HEAD
matching the tag only when the version was not forced, hence re-announce
already tagged versions after some extra commits were added for example.
diff --git a/scripts/announce-release b/scripts/announce-release
index 88274a0..385b18f 100755
--- a/scripts/announce-release
+++ b/scripts/announce-release
@@ -10,7 +10,14 @@
 #   - creates web-$version.html
 #   - indicates how to edit the mail and how to send it
 
-USAGE="Usage: ${0##*/} [-f] [-b branch] [-d date] [-o oldver] [-n newver]"
+USAGE="Usage: ${0##*/} [-f] [-b branch] [-d date] [-o oldver] [-n newver]
+  -f: force to overwrite existing files and ignore local changes
+  -b: force the project branch name to this (def: inherited from the version)
+  -d: force the release date (e.g. to rework a failed announce)
+  -o: previous version (def: newver-1)
+  -n: new version (if not last tag)
+"
+PREPARE=
 FORCE=
 OUTPUT=
 BRANCH=
@@ -18,7 +25,9 @@
 DATE=
 YEAR=
 OLD=
-NEW=
+LASTCOM=
+NEWVER=
+NEWTAG=
 DIR=
 
 die() {
@@ -41,7 +50,7 @@
 		-b)        BRANCH="$2"    ; shift 2 ;;
 		-f)        FORCE=1        ; shift   ;;
 		-o)        OLD="$2"       ; shift 2 ;;
-		-n)        NEW="$2"       ; shift 2 ;;
+		-n)        NEWVER="$2"    ; shift 2 ;;
 		-h|--help) quit "$USAGE" ;;
 		*)         die  "$USAGE" ;;
 	esac
@@ -59,33 +68,48 @@
 DIR="$PWD"
 cd $(git rev-parse --show-toplevel)
 
+if [ -z "$FORCE" -a "$(git diff HEAD|wc -c)" != 0 ]; then
+	err "You appear to have uncommitted local changes, please commit them first :"
+	git status -s -uno >&2
+	die
+fi
+
 if [ "$(git rev-parse --verify -q HEAD)" != "$(git rev-parse --verify -q master)" ]; then
 	die "git HEAD doesn't match master branch."
 fi
 
-if [ "$(git diff HEAD|wc -c)" != 0 ]; then
-	err "You appear to have uncommitted local changes, please commit them first :"
-	git status -s -uno >&2
-	die
+if [ -n "$NEWVER" ]; then
+	if git show-ref --tags "v$NEWVER" >/dev/null; then
+		NEWTAG="v$NEWVER"
+	else
+		echo "Note: no matching tag v$NEWVER, using HEAD".
+	fi
 fi
 
-if [ -z "$NEW" ]; then
-	NEW="$(git describe --tags HEAD --abbrev=0)"
-	NEW="${NEW#v}"
-	if [ -z "$NEW" ]; then
+# version unspecified or no existing tag for it
+if [ -z "$NEWTAG" ]; then
+	NEWTAG="$(git describe --tags HEAD --abbrev=0)"
+
+	if [ -z "$NEWTAG" ]; then
 		die "Fatal: cannot determine new version, please specify it."
-	fi
-	if [ "$(git describe --tags HEAD)" != "v$NEW" ]; then
-		die "Current version doesn't seem tagged, it reports $(git describe --tags "v$NEW"). Did you release it ?"
+
+	elif [ "$(git describe --tags HEAD)" != "$NEWTAG" ]; then
+		die "About to use current HEAD which doesn't seem tagged, it reports '$(git describe --tags HEAD 2>/dev/null)'. Did you release it ?"
 	fi
+elif ! git show-ref --tags "$NEWTAG" >/dev/null 2>&1; then
+	die "git tag $NEWTAG doesn't exist, did you create the release ?"
+fi
+
+if [ -z "$NEWVER" ]; then
+	NEWVER="${NEWTAG#v}"
 fi
 
-if ! git show-ref --tags "v$NEW" >/dev/null; then
-	die "git tag v$NEW doesn't exist, did you create the release ?"
+if [ -z "$LASTCOM" ]; then
+	LASTCOM="$(git rev-parse --short ${NEWTAG}^)"
 fi
 
 if [ -z "$OLD" ]; then
-	OLD="$(git describe --tags v${NEW}^ --abbrev=0)"
+	OLD="$(git describe --tags ${LASTCOM} --abbrev=0)"
 	OLD="${OLD#v}"
 fi
 
@@ -95,22 +119,22 @@
 
 # determine the product branch from the new release
 if [ -z "$BRANCH" ]; then
-	subvers=${NEW#[0-9]*.[0-9]*[-.]*[0-9].}
-	[ "${subvers}" = "${NEW}" ] && subvers=""
-	major=${NEW%.$subvers}
+	subvers=${NEWVER#[0-9]*.[0-9]*[-.]*[0-9].}
+	[ "${subvers}" = "${NEWVER}" ] && subvers=""
+	major=${NEWVER%.$subvers}
 	branch_ext=${major#*[0-9].*[0-9]}
 	BRANCH=${major%${branch_ext}}
 fi
 
 # determine the release date
 if [ -z "$DATE" ]; then
-	DATE="$(git log -1 --pretty=fuller v${NEW} 2>/dev/null | sed -ne '/^CommitDate:/{s/\(^[^ ]*:\)\|\( [-+].*\)//gp;q}')"
+	DATE="$(git log -1 --pretty=fuller ${NEWTAG} 2>/dev/null | sed -ne '/^CommitDate:/{s/\(^[^ ]*:\)\|\( [-+].*\)//gp;q}')"
 	DATE="$(date +%Y/%m/%d -d "$DATE")"
 fi
 YEAR="${DATE%%/*}"
 
-OUTPUT="$DIR/mail-haproxy-$NEW.txt"
-HTML="$DIR/web-haproxy-$NEW.html"
+OUTPUT="$DIR/mail-haproxy-$NEWVER.txt"
+HTML="$DIR/web-haproxy-$NEWVER.html"
 
 [ -z "$FORCE" ] || rm -f "${OUTPUT}" "${HTML}"
 
@@ -124,37 +148,37 @@
 
 (
  echo "# Send this using:"
- echo "#   mutt -H <(tail -n +4 ${OUTPUT##*/}) -s \"[ANNOUNCE] haproxy-$NEW\" haproxy@formilux.org"
+ echo "#   mutt -H <(tail -n +4 ${OUTPUT##*/}) -s \"[ANNOUNCE] haproxy-$NEWVER\" haproxy@formilux.org"
 ) >> "$OUTPUT"
 
 (echo
  echo "Hi,"
  echo
- echo -n "HAProxy $NEW was released on $DATE. It added "
- echo -n $(git log --oneline --reverse --format="%s" "v$OLD".."v$NEW^" | wc -l)
+ echo -n "HAProxy $NEWVER was released on $DATE. It added "
+ echo -n $(git log --oneline --reverse --format="%s" "v$OLD".."$LASTCOM" | wc -l)
  echo " new commits"
  echo "after version $OLD."
  echo
  echo "- per tag :"
- git log --oneline --reverse --format="%s" "v$OLD".."v$NEW^" | cut -f1 -d':' | sort | uniq -c
+ git log --oneline --reverse --format="%s" "v$OLD".."$LASTCOM" | cut -f1 -d':' | sort | uniq -c
  echo
  echo "major commits :"
- git log --oneline --reverse --format="  - %s" "v$OLD".."v$NEW^" | grep MAJOR
+ git log --oneline --reverse --format="  - %s" "v$OLD".."$LASTCOM" | grep MAJOR
  echo
  echo "- per file :"
- git show "v$OLD".."v$NEW^" -- src/ | grep ^diff | awk '{ print substr($3,7)}' | sort | uniq -c | sort -nr | head -15
+ git show "v$OLD".."$LASTCOM" -- src/ | grep ^diff | awk '{ print substr($3,7)}' | sort | uniq -c | sort -nr | head -15
  echo
  echo "- per topic :"
- git log --oneline --reverse --format="%s" "v$OLD".."v$NEW^" | cut -f2 -d':' | awk '{sub("s$","",$1); print $1}' | sort | uniq -c
+ git log --oneline --reverse --format="%s" "v$OLD".."$LASTCOM" | cut -f2 -d':' | awk '{sub("s$","",$1); print $1}' | sort | uniq -c
  echo
  echo "- sorted changelog :"
- git log --oneline --reverse --format="%s" "v$OLD".."v$NEW^" | sort
+ git log --oneline --reverse --format="%s" "v$OLD".."$LASTCOM" | sort
  echo
  echo "#############################################################################################"
 ) >> "$OUTPUT"
 
 # report the download paths
-if [ -z "${NEW##*-dev*}" ]; then
+if [ -z "${NEWVER##*-dev*}" ]; then
 	gitdir="haproxy.git"
 else
 	gitdir="haproxy-$BRANCH.git"
@@ -180,7 +204,7 @@
 
 (echo "---"
  echo "Complete changelog :"
- git shortlog "v$OLD".."v$NEW^"
+ git shortlog "v$OLD".."$LASTCOM"
  echo "---"
 ) >> "$OUTPUT"
 
@@ -196,18 +220,18 @@
 esac
 
 humandate=$(date "+%B, $day, %Y" -d "$DATE")
-(echo "$humandate</b> : <i>$NEW</i>"
+(echo "$humandate</b> : <i>$NEWVER</i>"
  echo "         <p>"
  echo "           <ul>"
  echo "<--------------------------- edit contents below --------------------------->"
  echo "- per tag :"
- git log --oneline --reverse --format="%s" "v$OLD".."v$NEW^" | cut -f1 -d':' | sort | uniq -c
+ git log --oneline --reverse --format="%s" "v$OLD".."$LASTCOM" | cut -f1 -d':' | sort | uniq -c
  echo
  echo "- per topic :"
- git log --oneline --reverse --format="%s" "v$OLD".."v$NEW^" | cut -f2 -d':' | awk '{sub("s$","",$1); print $1}' | sort | uniq -c
+ git log --oneline --reverse --format="%s" "v$OLD".."$LASTCOM" | cut -f2 -d':' | awk '{sub("s$","",$1); print $1}' | sort | uniq -c
  echo
  echo "major commits :"
- git log --oneline --reverse --format="  - %s" "v$OLD".."v$NEW^" | grep MAJOR
+ git log --oneline --reverse --format="  - %s" "v$OLD".."$LASTCOM" | grep MAJOR
  echo
  echo "<--------------------------------------------------------------------------->"
  echo "             Code and changelog are available <a href=\"/download/${BRANCH}/src/\">here</a> as usual."
@@ -219,7 +243,7 @@
 echo "The announce was emitted into file $OUTPUT."
 echo "You can edit it and send it this way :"
 echo
-echo "   mutt -H <(tail -n +4 ${OUTPUT##*/}) -s \"[ANNOUNCE] haproxy-$NEW\" haproxy@formilux.org"
+echo "   mutt -H <(tail -n +4 ${OUTPUT##*/}) -s \"[ANNOUNCE] haproxy-$NEWVER\" haproxy@formilux.org"
 echo
 echo "The HTML block was emitted into $HTML and needs to be finished by hand."
 echo