There was a double output redirection in this script while dumping the
current branch's refs which could cause either an error or an empty file.
WORK=.git/.show-backports
rm -f "$WORK/${REF//\//_}"
-git log --reverse ${LOGEXPR:+--grep $LOGEXPR} --pretty="%H %s" "$BASE".."$REF" | grep "${SUBJECT}" > "$WORK/${branch//\//_}" > "$WORK/${REF//\//_}"
+git log --reverse ${LOGEXPR:+--grep $LOGEXPR} --pretty="%H %s" "$BASE".."$REF" | grep "${SUBJECT}" > "$WORK/${REF//\//_}"
# for each branch, enumerate all commits and their ancestry