accounting: include disabled entries showing the GAP roots in report dialogs

Instead of having empty string items which for which the meaning is not
really clear.

bt5/erp5_accounting/SkinTemplateItem/portal_skins/erp5_accounting/Account_getGapItemList.py

@@ -7,32 +7,35 @@ categories from all available GAP.
 
 portal = context.getPortalObject()
 
-display_cache = {}
 def display(x):
-  if x not in display_cache:
-    gap_id = x.getReference()
-    if gap_id:
-      display_cache[x] = '%s - %s' % (
-        gap_id,
-        x.getTranslatedShortTitle() or x.getTranslatedTitle())
-    else:
-      display_cache[x] = x.getIndentedTitle()
+  gap_id = x.getReference()
+  if gap_id:
+    return '%s - %s' % (
+      gap_id,
+      x.getTranslatedShortTitle() or x.getTranslatedTitle())
+  return x.getIndentedTitle()
 
-  return display_cache[x]
 
 def getGapItemList(only_preferred_gap, gap_root=None):
-  if only_preferred_gap:
-    if gap_root:
-      return portal.portal_categories.resolveCategory(gap_root).getCategoryChildItemList(
-        base=False, is_self_excluded=True, display_method=display,
+  if only_preferred_gap and gap_root:
+    return portal.portal_categories.resolveCategory(gap_root).getCategoryChildItemList(
+        base=False,
+        is_self_excluded=True,
+        display_method=display,
+        display_none_category=False,
         local_sort_id=('int_index', 'reference', 'id'))
 
   result = []
-  for country in portal.portal_categories.gap.contentValues():
-    for gap_root in country.contentValues():
-      result.extend(gap_root.getCategoryChildItemList(
-        base=False, is_self_excluded=True, display_method=display,
-        local_sort_id=('int_index', 'reference', 'id')))
+  for gap_root_title, gap_root in context.AccountModule_getAvailableGapList():
+    if gap_root:
+      result.append((gap_root_title, None))
+      result.extend(
+          portal.portal_categories.resolveCategory(gap_root).getCategoryChildItemList(
+              base=False,
+              is_self_excluded=True,
+              display_method=display,
+              display_none_category=False,
+              local_sort_id=('int_index', 'reference', 'id')))
   return result
 
 from Products.ERP5Type.Cache import CachingMethod

bt5/erp5_accounting/SkinTemplateItem/portal_skins/erp5_accounting/Account_hashGapItemList.py

@@ -12,6 +12,8 @@ def getSubFieldDict():
     for item in item_list:
       # Get value of the item
       item_value = item[int(not is_right_display)]
+      if item_value is None:
+        continue
 
       # Hash key from item_value
       item_split = item_value.split('/')