Core: Correct log view thread handling

Fixes a crash when log messages are received from
multiple threads.

Fixes: QTCREATORBUG-30444
Change-Id: I51c78656da1dd30bcb51a801083d1714e474d8e5
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>

src/plugins/coreplugin/loggingviewer.cpp

@@ -559,10 +559,16 @@ private:
 
         const QString timestamp = QDateTime::currentDateTime().toString("HH:mm:ss.zzz");
 
+        auto append = [this, timestamp, type, category, msg] {
             if (rowCount() >= 1000000) // limit log to 1000000 items
                 destroyItem(itemForIndex(index(0, 0)));
-
             appendItem(LogEntry{timestamp, messageTypeToString(type), category, msg});
+        };
+
+        if (QThread::currentThread() != thread())
+            QMetaObject::invokeMethod(this, append, Qt::QueuedConnection);
+        else
+            append();
     }
 
 private: