Zone fill does not respect board boundaries when set to no net

[Mike Williams]

Create a board outline as shown in the attached image. Create a zone where some portion of it is outside of the outline. When filling the zone, if a net is selected, the zone will properly respect the board boundaries. If <no net> is selected it ignores the board outline.

Tested against 5.1.0.

[Seth Hillbrand (sethh)]

Related: https://bugs.launchpad.net/kicad/+bug/1811239

[Mike Williams (mikebwilliams)]

Application: kicad
Version: 5.1.0-060a0da~80~ubuntu18.04.1, release build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.58.0 OpenSSL/1.1.0g zlib/1.2.11 libidn2/2.0.4 libpsl/0.19.1 (+libidn2/2.0.4) nghttp2/1.30.0 librtmp/2.3
Platform: Linux 4.15.0-45-generic x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.22
    Boost: 1.65.1
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.58.0
    Compiler: GCC 7.3.0 with C++ ABI 1011

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

[Nick Østergaard (nickoe)]

I don't think this is a bug. This is how pcbnew has worked all the time. Also you can see the warning in the screenshot you posted.

[Seth Hillbrand (sethh)]

I think that if we are going to support filling no-net copper, then we shouldn't put it outside of the board if there is a closed outline.

[Wayne Stambaugh (stambaughw)]

I agree with Seth. I cannot think any use case where you would want copper outside of the board outline whether it is connected to a net or not. Unless someone can come up with a good argument as to why we should, I think we should fix this.

[Jeff Young (jeyjey)]

The fact that this works for zones /with/ nets is just a side-effect of unconnected areas not getting filled. If you add a track or pad to the outside region it will fill.

[KiCad Janitor (kicad-janitor)]

Fixed in revision 52e3a1d7c40d27ab855cf8b7ed46af3345e0ca58
https://git.launchpad.net/kicad/patch/?id=52e3a1d7c40d27ab855cf8b7ed46af3345e0ca58

[Seth Hillbrand (sethh)]

Hey Jeff, hat-tip on this one! Clean and elegant. I had been trying to figure out how to implement this but couldn't come up with anything decent. This solution is perfect. I think people often underestimate the short patches.

[KiCad Janitor (kicad-janitor)]

Fixed in revision 52e3a1d7c40d27ab855cf8b7ed46af3345e0ca58
https://git.launchpad.net/kicad/patch/?id=52e3a1d7c40d27ab855cf8b7ed46af3345e0ca58