Verify if date is a valid one

If git rev-list --before is called with date it cannot recognize, it
does not exits with error.

diff --git a/builder.sh b/builder.sh
index 101028b711fcc080dfb2e7ae2a7b7044954c126c..e406ab787c2b829c88d04a401d01e0b44c54ac56 100755 (executable)
--- a/builder.sh
+++ b/builder.sh
@@ -2079,7 +2079,9 @@ while [ $# -gt 0 ]; do
                -q | --quiet )
                        QUIET="--quiet"; shift ;;
                --date )
-                       CVSDATE="${2}"; shift 2 ;;
+                       CVSDATE="${2}"; shift 2
+                       date -d "$CVSDATE" > /dev/null 2>&1 || { echo >&2 "No valid date specified"; exit 3; }
+                       ;;
                -r | --cvstag )
                        CVSTAG="$2"
                        shift 2