loans: fix automatic item assignment on pending loans

Fixes problem when the checked-in item will be assigned to all
pending loans of its document. Fixed by adding the parameter
assign_item to all the ITEM_RETURNED transitions.

This PR needs any  invenio-circulation v.a21

* Fixes inveniosoftware/invenio-circulation#127.
* Removes the temporary transitions file used as a work around earlier.

Co-Authored-by: Aly Badr <aly.badr@rero.ch>

rero_ils/config.py

@@ -66,8 +66,6 @@
 from .modules.loans.api import Loan
 from .modules.loans.permissions import can_list_loan_factory, \
     can_read_loan_factory
-from .modules.loans.transitions import ItemInTransitHouseToItemReturned, \
-    ItemOnLoanToItemReturned
 from .modules.loans.utils import can_be_requested, get_default_loan_duration, \
     get_extension_params, is_item_available_for_checkout, \
     loan_build_document_ref, loan_build_item_ref, loan_build_patron_ref, \
@@ -1893,6 +1891,7 @@ def _(x):
             dest='ITEM_ON_LOAN',
             trigger='checkout',
             transition=ToItemOnLoan,
+            assign_item=False
         ),
     ],
     'PENDING': [
@@ -1920,17 +1919,25 @@ def _(x):
         dict(dest='CANCELLED', trigger='cancel', transition=ToCancelled)
     ],
     'ITEM_ON_LOAN': [
-        dict(dest='ITEM_RETURNED',
-             transition=ItemOnLoanToItemReturned, trigger='checkin'),
+        dict(
+            dest='ITEM_RETURNED',
+            transition=ItemOnLoanToItemReturned,
+            trigger='checkin',
+            assign_item=False
+        ),
         dict(dest='ITEM_IN_TRANSIT_TO_HOUSE',
              transition=ItemOnLoanToItemInTransitHouse, trigger='checkin'),
         dict(dest='ITEM_ON_LOAN', transition=ItemOnLoanToItemOnLoan,
              trigger='extend'),
         dict(dest='CANCELLED', trigger='cancel', transition=ToCancelled)
     ],
     'ITEM_IN_TRANSIT_TO_HOUSE': [
-        dict(dest='ITEM_RETURNED',
-             transition=ItemInTransitHouseToItemReturned, trigger='receive'),
+        dict(
+            dest='ITEM_RETURNED',
+            transition=ItemInTransitHouseToItemReturned,
+            trigger='receive',
+            assign_item=False
+        ),
         dict(dest='CANCELLED', trigger='cancel', transition=ToCancelled)
     ],
     'ITEM_RETURNED': [],