Bug 27586: Import patrons script has a confirm switch that doesn't nothing!

If the script misc/import_patrons.pl is run without "--confirm" it reports
that it is "running in dry-run mode" but it is not!

Test Plan:
1) Import a CSV of patrons using import_patrons.pm *without* the --confirm parameter
2) Note that it does actually import the patrons
3) Apply this patch
4) Note that this time the patrons are not actually imported
5) Import again with --confirm
6) Note that the patrons were actually imported this time!

Signed-off-by: David Nind <david@davidnind.com>

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

Koha/Patrons/Import.pm

@@ -73,9 +73,13 @@ sub import_patrons {
     my $ext_preserve         = $params->{preserve_extended_attributes};
     my $overwrite_cardnumber = $params->{overwrite_cardnumber};
     my $overwrite_passwords  = $params->{overwrite_passwords};
+    my $dry_run              = $params->{dry_run};
     my $extended             = C4::Context->preference('ExtendedPatronAttributes');
     my $set_messaging_prefs  = C4::Context->preference('EnhancedMessagingPreferences');
 
+    my $schema = Koha::Database->new->schema;
+    $schema->storage->txn_begin if $dry_run;
+
     my @columnkeys = $self->set_column_keys($extended);
     my @feedback;
     my @errors;
@@ -425,6 +429,8 @@ sub import_patrons {
         invalid       => $invalid,
         imported_borrowers => \@imported_borrowers,
     };
+
+    $schema->storage->txn_rollback if $dry_run;
 }
 
 =head2 prepare_columns

misc/import_patrons.pl

@@ -65,6 +65,7 @@ my $return = $Import->import_patrons(
         overwrite_cardnumber         => $overwrite_cardnumber,
         overwrite_passwords          => $overwrite_passwords,
         preserve_extended_attributes => $ext_preserve,
+        dry_run                      => !$confirm,
     }
 );