# HG changeset patch
# User Aurélien Campéas <aurelien.campeas@pythonian.fr>
# Date 1712666259 -7200
#      Tue Apr 09 14:37:39 2024 +0200
# Node ID 043dbc74159223f13f5e0a0e319c8a39f0848e22
# Parent  21bccec530bc885c3fbcc5482aaf34dae1002c7e
reduce_frequency: on empty stamps sequence, do not stop

Depending on the policy configuration this condition
can indeed happen in the wild.

diff --git a/tshistory_refinery/helper.py b/tshistory_refinery/helper.py
--- a/tshistory_refinery/helper.py
+++ b/tshistory_refinery/helper.py
@@ -63,7 +63,9 @@
 
 
 def reduce_frequency(tempo, idates):
-    assert len(tempo)
+    if not len(tempo):
+        return tempo
+
     assert len(idates)
     new_tempo = []
     for cdate in tempo: