From aea705505c794a5828e39f3bc038671fa90e7872 Mon Sep 17 00:00:00 2001
From: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Date: Wed, 13 Oct 2021 14:46:08 +0200
Subject: [PATCH] Bug 28739: Execute the letter processing inside a transaction

---
 C4/Letters.pm                            |  3 +++
 Koha/Object.pm                           | 17 +++++++++++++++++
 t/db_dependent/Letters/TemplateToolkit.t | 23 ++++++++++++++++++++++-
 3 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/C4/Letters.pm b/C4/Letters.pm
index f3cabc28565..5b53d96c326 100644
--- a/C4/Letters.pm
+++ b/C4/Letters.pm
@@ -1639,7 +1639,10 @@ sub _process_tt {
     $content = qq|[% USE KohaDates %][% USE Remove_MARC_punctuation %]$content|;
 
     my $output;
+    my $schema = Koha::Database->new->schema;
+    $schema->txn_begin;
     $template->process( \$content, $tt_params, \$output ) || croak "ERROR PROCESSING TEMPLATE: " . $template->error();
+    $schema->txn_rollback;
 
     return $output;
 }
diff --git a/Koha/Object.pm b/Koha/Object.pm
index 6f55c3b4861..e4b537bb5c5 100644
--- a/Koha/Object.pm
+++ b/Koha/Object.pm
@@ -374,6 +374,18 @@ sub add_message {
     my ( $self, $params ) = @_;
 
     push @{ $self->{_messages} }, Koha::Object::Message->new($params);
+}
+
+=head3 $object->read_only();
+
+Set the object as read_only, only getter methods will be allowed
+
+=cut
+
+sub read_only {
+    my ($self) = @_;
+
+    $self->{_read_only} = 1;
 
     return $self;
 }
@@ -811,6 +823,8 @@ sub AUTOLOAD {
     # Using direct setter/getter like $item->barcode() or $item->barcode($barcode);
     if ( grep { $_ eq $method } @columns ) {
         if ( @_ ) {
+            die "Setter method $method called on read-only object"
+                if $self->{_read_only};
             $self->_result()->set_column( $method, @_ );
             return $self;
         } else {
@@ -819,6 +833,9 @@ sub AUTOLOAD {
         }
     }
 
+    die "Cannot call method $method on a read-only object"
+        if $self->{_read_only};
+
     my @known_methods = qw( is_changed id in_storage get_column discard_changes make_column_dirty );
 
     Koha::Exceptions::Object::MethodNotCoveredByTests->throw(
diff --git a/t/db_dependent/Letters/TemplateToolkit.t b/t/db_dependent/Letters/TemplateToolkit.t
index 127a98bd117..e5905d53426 100755
--- a/t/db_dependent/Letters/TemplateToolkit.t
+++ b/t/db_dependent/Letters/TemplateToolkit.t
@@ -19,7 +19,7 @@
 # along with Koha; if not, see <http://www.gnu.org/licenses>.
 
 use Modern::Perl;
-use Test::More tests => 28;
+use Test::More tests => 29;
 use Test::MockModule;
 use Test::Warn;
 
@@ -1171,6 +1171,27 @@ EOF
     is( $letter->{content}, $expected_content );
 };
 
+subtest 'Execute TT process in a DB transaction' => sub {
+    plan tests => 2;
+    my $code = 'TEST_TXN';
+    my $library = $builder->build_object( { class => 'Koha::Libraries' } );
+    my $template = <<EOF;
+=[% branch.branchcode %]=
+[%~ branch.delete ~%]
+EOF
+    reset_template({ template => $template, code => $code, module => 'test' });
+    my $letter = GetPreparedLetter(
+        module      => 'test',
+        letter_code => $code,
+        tables      => {
+            branches => $library->branchcode,
+        }
+    );
+    my $branchcode = $library->branchcode;
+    like($letter->{content}, qr{=$branchcode=}, 'content generated with the library');
+    is( ref($library->get_from_storage), 'Koha::Library', 'calling ->delete on the object has not been comitted');
+};
+
 sub reset_template {
     my ( $params ) = @_;
     my $template   = $params->{template};
-- 
2.25.1