Bug 9201 OAI-PMH mapping value cannot be 0

Allow the value of a OAI set mapping to be 0 / empty. Delete the mapping if field or subfield are empty.

Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Now it is possible to add a value == 0 or an empty string.
Signed-off-by: Mason James <mtj@kohaaloha.com>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>

admin/oai_set_mappings.pl

@@ -60,7 +60,7 @@ if($op && $op eq "save") {
     my @mappings;
     my $i = 0;
     while($i < @marcfields and $i < @marcsubfields and $i < @marcvalues) {
-        if($marcfields[$i] and $marcsubfields[$i] and $marcvalues[$i]) {
+        if($marcfields[$i] and $marcsubfields[$i]) {
             push @mappings, {
                 marcfield    => $marcfields[$i],
                 marcsubfield => $marcsubfields[$i],