"/history" new policy for 'start' default.

That defaults to UIN64_MAX when delta is negative,
whereas it defaults to 0 with positive deltas.

2 files changed, 14 insertions, 7 deletions

diff --git a/taler-bank-manage.in b/taler-bank-manage.in
index d5c1dea..82f4156 100644
--- a/taler-bank-manage.in
+++ b/taler-bank-manage.in
@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+
 ##
 # This file is part of TALER
 # (C) 2017 INRIA
@@ -19,8 +21,6 @@
 #  @author Florian Dold
 #  @file CLI tool to manage all the bank's tasks.
 
-#!/usr/bin/env python3
-
 import argparse
 import django
 import sys
diff --git a/talerbank/app/views.py b/talerbank/app/views.py
index d3ff283..6d87e22 100644
--- a/talerbank/app/views.py
+++ b/talerbank/app/views.py
@@ -49,7 +49,7 @@ LOGGER = logging.getLogger(__name__)
 # Constant value for the biggest number the bank handles.
 # This value is just equal to the biggest number that JavaScript
 # can handle (because of the wallet).
-MAX_UINT64 = (2**64) - 1
+UINT64_MAX = (2**64) - 1
 
 
 ##
@@ -462,7 +462,7 @@ def logout_view(request):
 def extract_history(account,
                     descending,
                     delta=None,
-                    start=MAX_UINT64,
+                    start=UINT64_MAX,
                     sign="+"):
     history = []
     qs = query_history(account, "both", delta, start, sign, True)
@@ -630,19 +630,26 @@ def query_history(bank_account,
 @login_via_headers
 def serve_history(request, user_account):
     validate_data(request, request.GET.dict())
-    # delta
+
+    # delta (it does exist: enforced by the check above.)
     parsed_delta = re.search(r"([\+-])?([0-9]+)",
                              request.GET.get("delta"))
+    # normalize the sign.
     sign = parsed_delta.group(1)
+    sign = sign if sign else "+"
 
     # Ordering.
     ordering = request.GET.get("ordering", "descending")
+    start = request.GET.get("start")
+
+    if not start:
+        start = 0 if "+" == sign else UINT64_MAX
 
     qs = query_history(user_account.bankaccount,
                        request.GET.get("direction"),
                        int(parsed_delta.group(2)),
-                       int(request.GET.get("start", MAX_UINT64)),
-                       sign if sign else "+",
+                       int(start),
+                       sign,
                        "descending" == ordering)
 
     history = []