Do not run the Tesla sequence if no Turbo line fires.

For data this filter always passes, as Tesla only runs on the TURBO and
TURCAL streams, in which every event passes a Turbo line by
construction. In the simulation, however, this is not necessarily true,
so we protect the sequence from finding missing locations etc. by
filtering on Turbo decisions.

Phys/Tesla/python/Tesla/Configuration.py

@@ -900,6 +900,15 @@ class Tesla(LHCbConfigurableUser):
         if not streams:
             streams = {'': {'lines': trigger_lines}}
 
+        from DAQSys.Decoders import DecoderDB
+        hlt2dr_decoder = DecoderDB['HltDecReportsDecoder/Hlt2DecReportsDecoder'].setup()
+        # Cannot do anything if no Turbo(Calib) line fired (as then the DstData
+        # bank will be empty), so don't run subsequent algorithms
+        turbo_filter = HltDecReportsFilter('Hlt2_TeslaTurboFilter',
+                                           Code="HLT_TURBOPASS_RE('.*')")
+        turbo_filter_seq = GaudiSequencer('TeslaTurboFilter')
+        turbo_filter_seq.Members = [hlt2dr_decoder, turbo_filter]
+
         decoders_seq = GaudiSequencer('TeslaDecoders')
         if online:
             decoder_names = [
@@ -911,7 +920,6 @@ class Tesla(LHCbConfigurableUser):
             if vertex_report_location == 'Hlt1':
                 decoder_names.insert(0, 'HltVertexReportsDecoder/Hlt1VertexReportsDecoder')
             for name in decoder_names:
-                from DAQSys.Decoders import DecoderDB
                 decoder = DecoderDB[name].setup()
                 decoders_seq.Members.append(decoder)
 
@@ -984,8 +992,9 @@ class Tesla(LHCbConfigurableUser):
             ),
             IgnoreFilterPassed=True
         )
+        turbo_filter_seq.Members.append(streaming_seq)
 
-        return streaming_seq
+        return turbo_filter_seq
 
     def _configureOutputTurboSPStream(self, name, lines, packing, online,
                                       raw_format_output):