Check for product_set errors

+ update specs: can't save variant that is not well filled. Now display errors (instead of a generic one)

app/controllers/spree/admin/products_controller.rb

@@ -76,7 +76,7 @@ module Spree
 
         product_set.collection.each { |p| authorize! :update, p }
 
-        if product_set.save
+        if product_set.save && product_set.errors.empty?
           redirect_to main_app.bulk_products_api_v0_products_path(bulk_index_query)
         elsif product_set.errors.present?
           render json: { errors: product_set.errors }, status: :bad_request

spec/system/admin/bulk_product_update_spec.rb

@@ -303,7 +303,6 @@ describe '
       end
 
       it "creating a variant with unit value is: '120g' and 'on_hand' filled" do
-        pending "#9068"
         within "tr#v_#{Spree::Variant.second.id}" do
           page.find(".add-variant").click
         end
@@ -315,11 +314,10 @@ describe '
         end
 
         click_button 'Save Changes', match: :first
-        expect(page.find("#status-message")).to have_content "Changes saved."
+        expect(page.find("#status-message")).to have_content "Unit value can't be blank Unit value is not a number"
       end
 
       it "creating a variant with unit value is: '120g' and 'on_demand' checked" do
-        pending "#9068"
         within "tr#v_#{Spree::Variant.second.id}" do
           page.find(".add-variant").click
         end
@@ -331,7 +329,7 @@ describe '
         end
 
         click_button 'Save Changes', match: :first
-        expect(page.find("#status-message")).to have_content "Changes saved."
+        expect(page.find("#status-message")).to have_content "Unit value can't be blank Unit value is not a number"
       end
     end
   end