It's good but not wanted behaviour. qInstallMessageHandler documentation contains such snippet.

      case QtFatalMsg:
          fprintf(stderr, "Fatal: %s (%s:%u, %s)\n", localMsg.constData(), context.file, context.line, context.function);
          abort();

Here is abort() used. But abort will be always called. It happens in qlogging.cpp qt_message_fatal function.

So qInstallMessageHandler documentation should be improved. Need to remove abort() and add QtFatalMsg explanation.