Bug 13215: Fix GetLetterTemplates should return default templates if branchcode is not defined

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>

C4/Letters.pm

@@ -115,7 +115,7 @@ sub GetLetterTemplates {
 
     my $module    = $params->{module};
     my $code      = $params->{code};
-    my $branchcode = $params->{branchcode};
+    my $branchcode = $params->{branchcode} // '';
     my $dbh       = C4::Context->dbh;
     my $letters   = $dbh->selectall_hashref(
         q|

t/db_dependent/Letters/GetLetterTemplates.t

@@ -1,5 +1,5 @@
 use Modern::Perl;
-use Test::More tests => 6;
+use Test::More tests => 7;
 
 use C4::Context;
 use C4::Letters qw( GetLetterTemplates );
@@ -123,3 +123,8 @@ is( scalar( keys %$letter_templates ),
     1, '1 template should exist for circulation CPL code1' );
 is( exists( $letter_templates->{email} ),
     1, 'The mtt should be email for circulation CPL code1' );
+
+$letter_templates = C4::Letters::GetLetterTemplates(
+    { module => 'circulation', code => 'code1' } );
+is( scalar( keys %$letter_templates ),
+    2, '2 default templates should exist for circulation code1 (even if branchcode is not given)' );