erp5_base: minimum bound of quantity_step_list should be 0

we don't support negative quantity (it is better represented by an
inversion of source and destination), and this allows better support of
the smallest slice in ERP5, more especially in SupplyLine_asCellRange,
where the title of the cell is computed with the min and max being None
or not.

bt5/erp5_base/DocumentTemplateItem/portal_components/document.erp5.SupplyLine.py

@@ -201,7 +201,7 @@ class SupplyLine(Path, Amount, XMLMatrix):
     unused_predicate_id_set = self.getQuantityPredicateIdList(price_parameter)
     if quantity_step_list:
       quantity_step_list.sort()
-      quantity_step_list = [None] + quantity_step_list + [None]
+      quantity_step_list = [0] + quantity_step_list + [None]
       getTitle = getattr(
         self,
         'SupplyLine_getTitle',

bt5/erp5_pdm/SkinTemplateItem/portal_skins/erp5_pdm/Resource_getPriceCalculationOperandDict.py

@@ -29,7 +29,7 @@ if result["slice_base_price"]:
     slice_min, slice_max = slice_range
     if slice_max is None:
       slice_max = quantity + 1
-    if slice_min is None:
+    if slice_min == 0:
       slice_min = 1
     priced_quantity = min(slice_max - 1, quantity) - (slice_min - 1)
     total_price += priced_quantity * slice_price

bt5/erp5_pdm/SkinTemplateItem/portal_skins/erp5_pdm/SupplyCell_updateSliceBasePrice.py

@@ -7,7 +7,7 @@ if not quantity_criterion_list:
 quantity_criterion, = quantity_criterion_list
 supply_line_value = context.getParentValue()
 if supply_line_value.isBasePricePerSlice():
-  quantity_step_list = [None] + supply_line_value.getQuantityStepList(base_id='path') + [None]
+  quantity_step_list = [0] + supply_line_value.getQuantityStepList(base_id='path') + [None]
   try:
     index = quantity_step_list.index(quantity_criterion.min)
   except ValueError:

bt5/erp5_pdm_ui_test/PathTemplateItem/portal_tests/pdm_zuite/resource_default_internal_supply_line_price_per_slice.zpt

@@ -39,7 +39,7 @@ Test toggling price per slice updates internal supply cells correctly
 <tr>
   <td>assertText</td>
   <td>//input[@name="field_matrixbox_base_price_cell_0_0_0"]/../../../td[1]</td>
-  <td>Quantity &lt; 11.0</td>
+  <td>0 &lt;= Quantity &lt; 11.0</td>
 </tr>
 <tr>
   <td>assertText</td>

bt5/erp5_pdm_ui_test/PathTemplateItem/portal_tests/pdm_zuite/resource_default_internal_supply_line_price_quantity_step.zpt

@@ -36,7 +36,7 @@ Test quantity steps for price on internal supply line
 <tr>
   <td>assertText</td>
   <td>//input[@name="field_matrixbox_base_price_cell_0_0_0"]/../../../td[1]</td>
-  <td>Quantity &lt; 10.0</td>
+  <td>0 &lt;= Quantity &lt; 10.0</td>
 </tr>
 <tr>
   <td>assertText</td>

bt5/erp5_pdm_ui_test/PathTemplateItem/portal_tests/pdm_zuite/resource_default_purchase_supply_line_price_per_slice.zpt

@@ -39,7 +39,7 @@ Test toggling price per slice updates purchase supply cells correctly
 <tr>
   <td>assertText</td>
   <td>//input[@name="field_matrixbox_base_price_cell_0_0_0"]/../../../td[1]</td>
-  <td>Quantity &lt; 11.0</td>
+  <td>0 &lt;= Quantity &lt; 11.0</td>
 </tr>
 <tr>
   <td>assertText</td>

bt5/erp5_pdm_ui_test/PathTemplateItem/portal_tests/pdm_zuite/resource_default_purchase_supply_line_price_quantity_step.zpt

@@ -36,7 +36,7 @@ Test quantity steps for price on purchase supply line
 <tr>
   <td>assertText</td>
   <td>//input[@name="field_matrixbox_base_price_cell_0_0_0"]/../../../td[1]</td>
-  <td>Quantity &lt; 10.0</td>
+  <td>0 &lt;= Quantity &lt; 10.0</td>
 </tr>
 <tr>
   <td>assertText</td>

bt5/erp5_pdm_ui_test/PathTemplateItem/portal_tests/pdm_zuite/resource_default_sale_supply_line_price_per_slice.zpt

@@ -39,7 +39,7 @@ Test toggling price per slice updates sale supply cells correctly
 <tr>
   <td>assertText</td>
   <td>//input[@name="field_matrixbox_base_price_cell_0_0_0"]/../../../td[1]</td>
-  <td>Quantity &lt; 11.0</td>
+  <td>0 &lt;= Quantity &lt; 11.0</td>
 </tr>
 <tr>
   <td>assertText</td>

bt5/erp5_pdm_ui_test/PathTemplateItem/portal_tests/pdm_zuite/resource_default_sale_supply_line_price_quantity_step.zpt

@@ -36,7 +36,7 @@ Test quantity steps for price on sale supply line
 <tr>
   <td>assertText</td>
   <td>//input[@name="field_matrixbox_base_price_cell_0_0_0"]/../../../td[1]</td>
-  <td>Quantity &lt; 10.0</td>
+  <td>0 &lt;= Quantity &lt; 10.0</td>
 </tr>
 <tr>
   <td>assertText</td>

bt5/erp5_trade/TestTemplateItem/portal_components/test.erp5.testResource.py

@@ -1266,10 +1266,10 @@ class TestResource(ERP5TypeTestCase):
       portal_type=self.sale_supply_cell_portal_type,
       id='path_0',
       slice_base_price=10.,
-      slice_quantity_range=(1, 11),
+      slice_quantity_range=(0, 11),
     )
     cell0.setCriterionPropertyList(('quantity', ))
-    cell0.setCriterion('quantity', min=1, max=None)
+    cell0.setCriterion('quantity', min=0, max=None)
     cell0.setMappedValuePropertyList(
       ["slice_base_price", "slice_quantity_range", "base_price", "base_unit_price"]
     )

bt5/erp5_trade_ui_test/PathTemplateItem/portal_tests/trade_zuite/testInternalSupplyLinePricePerSlice.zpt

@@ -101,7 +101,7 @@ Test quantity steps for price on internal supply line
 <tr>
   <td>assertText</td>
   <td>//input[@name="field_matrixbox_base_price_cell_0_0_0"]/../../../td[1]</td>
-  <td>Quantity &lt; 11.0</td>
+  <td>0 &lt;= Quantity &lt; 11.0</td>
 </tr>
 <tr>
   <td>assertText</td>

bt5/erp5_trade_ui_test/PathTemplateItem/portal_tests/trade_zuite/testPurchaseSupplyLinePricePerSlice.zpt

@@ -101,7 +101,7 @@ Test quantity steps for price on purchase supply line
 <tr>
   <td>assertText</td>
   <td>//input[@name="field_matrixbox_base_price_cell_0_0_0"]/../../../td[1]</td>
-  <td>Quantity &lt; 11.0</td>
+  <td>0 &lt;= Quantity &lt; 11.0</td>
 </tr>
 <tr>
   <td>assertText</td>

bt5/erp5_trade_ui_test/PathTemplateItem/portal_tests/trade_zuite/testSaleSupplyLinePricePerSlice.zpt

@@ -100,7 +100,7 @@ Test quantity steps for price on sale supply line
 <tr>
   <td>assertText</td>
   <td>//input[@name="field_matrixbox_base_price_cell_0_0_0"]/../../../td[1]</td>
-  <td>Quantity &lt; 11.0</td>
+  <td>0 &lt;= Quantity &lt; 11.0</td>
 </tr>
 <tr>
   <td>assertText</td>