Bug 23900: Teach label maker to concat database fields

Test plan:
- define a label layout with this field list: "100a 245s","enumchron copynumber"
- find or create a record with values for all of those fields
- generate a label for that record
- the 100a and 245s successfully display on one line
- the enumchron and copynumber are displayed and separated by a space

Try other combinations

Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

C4/Labels/Label.pm

@@ -148,11 +148,16 @@ sub _get_barcode_data {
             next FIELD_LIST;
         }
         elsif ( $f =~ /^($match_kohatable).*/ ) {
-            if ($item->{$f}) {
-                $datastring .= $item->{$f};
-            } else {
-                $debug and warn sprintf("The '%s' field contains no data.", $f);
+            my @fields = split ' ', $f;
+            my @data;
+            for my $field ( @fields ) {
+                if ($item->{$field}) {
+                    push @data, $item->{$field};
+                } else {
+                    $debug and warn sprintf("The '%s' field contains no data.", $field);
+                }
             }
+            $datastring .= join ' ', @data;
             $f = $';
             next FIELD_LIST;
         }