Fix memory release issue when added protocol decoder

DSView/pv/data/decoderstack.cpp

@@ -213,6 +213,8 @@ void DecoderStack::clear()
 
 void DecoderStack::stop_decode()
 {
+    _snapshot.reset();
+
     if(_decode_state == Stopped)
         return;
 

DSView/pv/dock/protocoldock.cpp

@@ -103,10 +103,10 @@ int ProtocolDock::decoder_name_cmp(const void *a, const void *b)
 
 void ProtocolDock::paintEvent(QPaintEvent *)
 {
-     QStyleOption opt;
-     opt.init(this);
-     QPainter p(this);
-     style()->drawPrimitive(QStyle::PE_Widget, &opt, &p, this);
+     //QStyleOption opt;
+     //opt.init(this);
+     //QPainter p(this);
+     //style()->drawPrimitive(QStyle::PE_Widget, &opt, &p, this);
 }
 
 void ProtocolDock::add_protocol()

DSView/pv/sigsession.cpp

@@ -608,6 +608,13 @@ void SigSession::read_sample_rate(const sr_dev_inst *const sdi)
 
 void SigSession::feed_in_header(const sr_dev_inst *sdi)
 {
+#ifdef ENABLE_DECODE
+    for (vector< boost::shared_ptr<view::DecodeTrace> >::iterator i =
+        _decode_traces.begin();
+        i != _decode_traces.end();
+        i++)
+        (*i)->decoder()->stop_decode();
+#endif
     read_sample_rate(sdi);
     //receive_data(0);
 }
@@ -1098,13 +1105,7 @@ void SigSession::data_feed_in(const struct sr_dev_inst *sdi,
             _cur_dso_snapshot.reset();
             _cur_analog_snapshot.reset();
 		}
-#ifdef ENABLE_DECODE
-        for (vector< boost::shared_ptr<view::DecodeTrace> >::iterator i =
-            _decode_traces.begin();
-            i != _decode_traces.end();
-            i++)
-            (*i)->decoder()->stop_decode();
-#endif
+
         frame_ended();
 		break;
 	}