support/download/cvs: add support to use a date instead of a tag

This is useful when a tag is not avaiable.

Also fix support for Fedora where the command "cvs -r :<version>" doesn't work.

Signed-off-by: Fabio Porcedda <fabio.porcedda@gmail.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

support/download/cvs

@@ -26,7 +26,16 @@ rev="${3}"
 rawname="${4}"
 basename="${5}"
 
+if [[ ${rev} =~ ^[0-9] ]]; then
+    # Date, because a tag or a branch cannot begin with a number
+    select="-D"
+else
+    # Tag or branch
+    select="-r"
+fi
+
+export TZ=UTC
 ${CVS} ${verbose} -z3 -d":pserver:anonymous@${repo}" \
-       co -d "${basename}" -r ":${rev}" -P "${rawname}"
+       co -d "${basename}" ${select} "${rev}" -P "${rawname}"
 
 tar czf "${output}" "${basename}"