[IMP] product: Remove field Category Type on product category

Purpose
=======

It is possible to break the installation of any module if a module that creates a product should be installed.

to reproduce:
set "all" as category of one product
then change "all" category to view type
then install pos (because pos installs one product)

you will get the error message in a traceback

See https://www.odoo.com/web#id=748876&view_type=form&model=project.issue&action=963&active_id=49&menu_id=4720

Specs
=====

remove "Category type" in categories

it seems to me the only usefulness of this was the deprecated tree view of product categories (no longer exists)

addons/product/models/product.py

@@ -27,10 +27,6 @@ class ProductCategory(models.Model):
         store=True)
     parent_id = fields.Many2one('product.category', 'Parent Category', index=True, ondelete='cascade')
     child_id = fields.One2many('product.category', 'parent_id', 'Child Categories')
-    type = fields.Selection([
-        ('view', 'View'),
-        ('normal', 'Normal')], 'Category Type', default='normal',
-        help="A category of the view type is a virtual category that can be used as the parent of another category to create a hierarchical structure.")
     parent_left = fields.Integer('Left Parent', index=1)
     parent_right = fields.Integer('Right Parent', index=1)
     product_count = fields.Integer(

addons/product/models/product_template.py

@@ -21,14 +21,12 @@ class ProductTemplate(models.Model):
         if self._context.get('categ_id') or self._context.get('default_categ_id'):
             return self._context.get('categ_id') or self._context.get('default_categ_id')
         category = self.env.ref('product.product_category_all', raise_if_not_found=False)
-        if category and category.type == 'normal':
-            return category.id
-        # fallback if no category "All" exists, because yes, users do delete default data!
-        category = self.env['product.category'].search([('type', '=', 'normal')], limit=1)
+        if not category:
+            category = self.env['product.category'].search([], limit=1)
         if category:
             return category.id
         else:
-            err_msg = _('You must define at least one product category (that is not a view) in order to be able to create products.')
+            err_msg = _('You must define at least one product category in order to be able to create products.')
             redir_msg = _('Go to Internal Categories')
             raise RedirectWarning(err_msg, self.env.ref('product.product_category_action_form').id, redir_msg)
 
@@ -59,7 +57,7 @@ class ProductTemplate(models.Model):
     rental = fields.Boolean('Can be Rent')
     categ_id = fields.Many2one(
         'product.category', 'Internal Category',
-        change_default=True, default=_get_default_category_id, domain="[('type','=','normal')]",
+        change_default=True, default=_get_default_category_id,
         required=True, help="Select category for the current product")
 
     currency_id = fields.Many2one(
@@ -265,11 +263,6 @@ class ProductTemplate(models.Model):
             if len(p.product_variant_ids) == 1:
                 p.product_variant_ids.packaging_ids = p.packaging_ids
 
-    @api.constrains('categ_id')
-    def _check_category(self):
-        if self.categ_id.type == 'view':
-            raise ValidationError(_("You cannot create a product with an Internal Category set as View. Please change the category or the category type."))
-
     @api.constrains('uom_id', 'uom_po_id')
     def _check_uom(self):
         if any(template.uom_id and template.uom_po_id and template.uom_id.category_id != template.uom_po_id.category_id for template in self):

addons/product/views/product_views.xml

@@ -421,9 +421,8 @@
                             <label for="name" string="Category name" class="oe_edit_only"/>
                             <h1><field name="name" placeholder="e.g. Lamps"/></h1>
                         </div>
-                        <group name="first" col="4" string="Category Type">
-                            <field name="parent_id"/>
-                            <field name="type"/>
+                        <group name="first" col="2">
+                            <field name="parent_id" class="oe_inline"/>
                         </group>
                     </sheet>
                 </form>