Since Quotes moved to sidecar in 7.9 if you add custom field to Products module and add them to ./custom/modules/Products/clients/base/views/quote-data-group-list/quote-data-group-list.php according to: http://support.sugarcrm.com/Documentation/Sugar_Developer/Sugar_Developer_Guide_7.9/Architecture/Quotes/index.html#Modif… custom field is editable, can be saved etc. but if you reload page custom fields won't be loaded because API won't return them.
Workaround for this is to edit custom/modules/Quotes/clients/base/views/record/record.php (copy it from module if it doesn't already exist) and under panels/panel_header/fields/name/related_fields/product_bundle_items/fields add your custom fields:
'panels' =>
array (
0 =>
array (
'name' => 'panel_header',
'label' => 'LBL_PANEL_HEADER',
'header' => true,
'fields' =>
array (
array (
'name' => 'name',
'events' =>
array (
'keyup' => 'update:quote',
),
'related_fields' =>
array (
0 =>
array (
'name' => 'bundles',
'fields' =>
array (
/*...*/
27 =>
array (
'name' => 'product_bundle_items',
'fields' =>
array (
/*...*/
17 => 'total_amount',
18 => 'my_custom_field_c',
),
