Comment 23 for bug 1803808

As reported in https://bugs.launchpad.net/ubuntu/+bug/1803808, the issue cannot be reproduced on 3.0, but only 2.6. Bisection led up to:

3a0da5fbb2c907eb90701275555aefd1a8e2415c is the first bad commit
commit 3a0da5fbb2c907eb90701275555aefd1a8e2415c
Date: Mon Jul 16 09:06:39 2018 -0700

    Qt: Create the main display filter combo sooner.

    Construct MainWindow::df_combo_box_ in our initializer list, otherwise
    anything that triggers a resizeEvent early on might result in an NPE.

    Wait until everything is in place before calling setMinimumWidth.

    Conflicts:
        ui/qt/main_window.cpp

    Bug: 14979
    Change-Id: I78b349f9c3ea53d8b1399a77169bbbd0a4a69191
    Reviewed-on: https://code.wireshark.org/review/28728
    Petri-Dish: Gerald Combs <email address hidden>
    Tested-by: Petri Dish Buildbot
    Reviewed-by: Gerald Combs <email address hidden>
    (cherry picked from commit 2cfa3013bc2890dd1ea8468366344c3d3878f3a0)
    Reviewed-on: https://code.wireshark.org/review/28746

The issue was likely (unintentionally?) resolved in v2.9.0rc0-2728-gabfe9572bd.