Extra 'Default' netclass added when GetAllNetClasses() called

[Richard Graham]

When using the python API, calling board.GetAllNetClasses() causes an extra duplicate copy of the Default netclass to show up in the design rules net classes list.

This is because the netclass map for the board is being modified. A comment in the source code already notes that this may happen and suggests a fix. This should be implemented.

See pcbnew.py

20766 # Add the Default one too, but this is probably modifying the NETCLASS_MAP
20767 # in the BOARD. If that causes trouble, could make a deepcopy() here first.
20768 # netclassmap = deepcopy(netclassmap)

Kicad version info below:

Application: kicad
Version: 6.0.0-rc1-unknown-r14229.44d416caf.fc27, debug build
Libraries:
    wxWidgets 3.0.2
    libcurl/7.55.1 OpenSSL/1.1.0i zlib/1.2.11 libidn2/2.0.5 libpsl/0.18.0 (+libidn2/2.0.4) libssh2/1.8.0 nghttp2/1.31.1
Platform: Linux 4.18.16-100.fc27.x86_64 x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.0.2 (wchar_t,wx containers,compatible with 2.8) GTK+ 2.24
    Boost: 1.64.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.55.1
    Compiler: GCC 7.3.1 with C++ ABI 1011

Build settings:
    USE_WX_GRAPHICS_CONTEXT=OFF
    USE_WX_OVERLAY=OFF
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_PYTHON3=OFF
    KICAD_SCRIPTING_WXPYTHON=ON
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON

[KiCad Janitor (kicad-janitor)]

Fixed in revision 44734dc05993d9ec19569b64b75af7de06e52c81
https://git.launchpad.net/kicad/patch/?id=44734dc05993d9ec19569b64b75af7de06e52c81