Don't send dataChanged for newly added sessions

In the session listing model. This ends up confusing QSortFilterProxy
somehow, causing it to potentially run into a crash.

ChangeLog

@@ -1,6 +1,7 @@
 Unreleased Version 2.2.2-pre
  * Fix: Use more accurate timers for performance profiles if the platform supports it.
  * Fix: Don't try to update the roles list before becoming an operator, which could lead to a crash. Thanks Bluestrings for reporting.
+ * Fix: Don't update sessions that were just added to the session browser, since that can lead to a crash because of what is probably a bug in Qt's filtering and sorting. Thanks Bluestrings for reporting.
 
 2024-08-04 Version 2.2.2-beta.2
  * Feature: Allow choosing a different cursor for erase and alpha locked brushes. Thanks Hipofiz and Rylan for suggesting.

src/libclient/net/sessionlistingmodel.cpp

@@ -2,6 +2,7 @@
 #include "libclient/net/sessionlistingmodel.h"
 #include "libclient/net/loginsessions.h"
 #include "libclient/parentalcontrols/parentalcontrols.h"
+#include "libshared/util/qtcompat.h"
 #include <QFont>
 #include <QIcon>
 #include <QPalette>
@@ -501,10 +502,14 @@ void SessionListingModel::setList(
 			}
 
 			emit dataChanged(createIndex(i, 0), createIndex(i, 0));
-			emit dataChanged(
-				createIndex(0, 0, quintptr(i + 1)),
-				createIndex(
-					sessions.size() - 1, ColumnCount - 1, quintptr(i + 1)));
+
+			compat::sizetype changedSize = qMin(oldSize, sessions.size());
+			if(changedSize > 0) {
+				emit dataChanged(
+					createIndex(0, 0, quintptr(i + 1)),
+					createIndex(
+						changedSize - 1, ColumnCount - 1, quintptr(i + 1)));
+			}
 			return;
 		}
 	}