MainWindow: fixed some bugs related to handling of null transport in …

…in add-instrument menu. Fixes #777.

src/ngscopeclient/MainWindow.cpp

@@ -1490,7 +1490,9 @@ void MainWindow::AddToRecentInstrumentList(shared_ptr<SCPIInstrument> inst)
 	if(inst == nullptr)
 		return;
 
-	LogTrace("Adding instrument \"%s\" to recent instrument list\n", inst->m_nickname.c_str());
+	LogTrace("Adding instrument \"%s\" to recent instrument list (had %zu)\n",
+		inst->m_nickname.c_str(), m_recentInstruments.size());
+	LogIndenter li;
 
 	auto now = time(NULL);
 
@@ -1499,6 +1501,7 @@ void MainWindow::AddToRecentInstrumentList(shared_ptr<SCPIInstrument> inst)
 		inst->GetDriverName() + ":" +
 		inst->GetTransportName() + ":" +
 		inst->GetTransportConnectionString();
+	LogTrace("Connection string: %s\n", connectionString.c_str());
 	m_recentInstruments[connectionString] = now;
 
 	//Delete anything old
@@ -1517,8 +1520,12 @@ void MainWindow::AddToRecentInstrumentList(shared_ptr<SCPIInstrument> inst)
 			}
 		}
 
+		LogTrace("Removing oldest instrument (%s) to make room\n", oldestPath.c_str());
 		m_recentInstruments.erase(oldestPath);
 	}
+
+	LogTrace("Added (now have %zu total recent instruments)\n", m_recentInstruments.size());
+	SaveRecentInstrumentList();
 }
 
 /**

src/ngscopeclient/MainWindow_Menus.cpp

@@ -322,8 +322,17 @@ void MainWindow::DoAddSubMenu(
 			for(auto cstring : cstrings)
 			{
 				auto fields = explode(cstring, ':');
+
+				//make sure it's well formed
 				if(fields.size() < 4)
-					continue;
+				{
+					//Special case: null transport allows 3 fields
+					if( (fields.size() == 3) && (fields[2] == "null") )
+					{}
+
+					else
+						continue;
+				}
 
 				auto nick = fields[0];
 				auto drivername = fields[1];
@@ -333,9 +342,13 @@ void MainWindow::DoAddSubMenu(
 				{
 					if(ImGui::MenuItem(nick.c_str()))
 					{
-						auto path = fields[3];
-						for(size_t j=4; j<fields.size(); j++)
-							path = path + ":" + fields[j];
+						string path;
+						if(fields.size() >= 4)
+						{
+							path = fields[3];
+							for(size_t j=4; j<fields.size(); j++)
+								path = path + ":" + fields[j];
+						}
 
 						auto transport = MakeTransport(transname, path);
 						if(transport != nullptr)