Bug 25852: Improve C4::Creators::Lib reliability under plack

This is certainly a major issue that leads to many side-effects.
Under plack, the structure of the default values are not handled
correctly.
Package variables are used to store stuff like the "layout type". They
are complex structures (arrays of hashes) and returned without being
copied.
When the caller (the controller script) retrieve them then modify the
returned structures, it actually modifies the package's variables.

One of the issue is:
Create a new layout
The script retrieve a structure with all "selected" flags are set to 0
It select the first one as default (BAR as selected => 1)
The user creates the new layout and will selected BIBBAR (for instance)
If you then edit this new layout, the script will retrieve the
"label_types" and set "selected" for BIBBAR. However BAR is still
selected!
The UI receives 2 selected and display the first selected one that has
the selected option.

Test plan:
1. Create a layout type for Barcode/Biblio
2. Choose fields to print and size of font
3. Save
4. Edit existing Layout
=> Withtout this patch "Barcode" is the preselected option
=> With this patch applied, the correct "Barcode/Biblio" option is
selected

Signed-off-by: Kelly McElligott <kelly@bywatersolutions.com>

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

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

C4/Creators/Lib.pm

@@ -17,8 +17,8 @@ package C4::Creators::Lib;
 # You should have received a copy of the GNU General Public License
 # along with Koha; if not, see <http://www.gnu.org/licenses>.
 
-use strict;
-use warnings;
+use Modern::Perl;
+use Storable qw(dclone);
 
 use autouse 'Data::Dumper' => qw(Dumper);
 
@@ -405,7 +405,7 @@ This function returns a reference to an array of hashes containing all barcode t
 =cut
 
 sub get_barcode_types {
-    return $barcode_types;
+    return dclone $barcode_types;
 }
 
 =head2 C4::Creators::Lib::get_label_types()
@@ -417,7 +417,7 @@ This function returns a reference to an array of hashes containing all label typ
 =cut
 
 sub get_label_types {
-    return $label_types;
+    return dclone $label_types;
 }
 
 =head2 C4::Creators::Lib::get_font_types()
@@ -429,7 +429,7 @@ This function returns a reference to an array of hashes containing all font type
 =cut
 
 sub get_font_types {
-    return $font_types;
+    return dclone $font_types;
 }
 
 =head2 C4::Creators::Lib::get_text_justification_types()
@@ -441,7 +441,7 @@ This function returns a reference to an array of hashes containing all text just
 =cut
 
 sub get_text_justification_types {
-    return $text_justification_types;
+    return dclone $text_justification_types;
 }
 
 =head2 C4::Creators::Lib::get_unit_values()
@@ -455,7 +455,7 @@ There are 72 PS points to the inch.
 =cut
 
 sub get_unit_values {
-    return $unit_values;
+    return dclone $unit_values;
 }
 
 =head2 C4::Creators::Lib::get_output_formats()
@@ -467,7 +467,7 @@ This function returns a reference to an array of hashes containing all label out
 =cut
 
 sub get_output_formats {
-    return $output_formats;
+    return dclone $output_formats;
 }