New Connectivity splits nets on import from Eagle

[Seth Hillbrand]

The new connectivity algorithm re-opens lp:1788019 by splitting the nets on import. Since Eagle allows wires crossing pins without connecting, our import must also allow this or we connect nets incorrectly in ways that are really difficult to find.

Application: Eeschema
Version: (5.1.0-698-g40382f4d5), release build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.64.0 OpenSSL/1.1.1b zlib/1.2.11 libidn2/2.0.5 libpsl/0.20.2 (+libidn2/2.0.5) libssh2/1.8.0 nghttp2/1.36.0 librtmp/2.3
Platform: Linux 4.19.0-4-amd64 x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
    Boost: 1.67.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.64.0
    Compiler: GCC 8.3.0 with C++ ABI 1013

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

[Jon Evans (craftyjon)]

I'm not sure the details here, but is this actually a connectivity algo thing, or is it a schematic cleanup thing (adding junctions)?

[Seth Hillbrand (sethh)]

It is just schematic cleanup. Sorry, I should have tagged myself here.

[Jon Evans (craftyjon)]

I'm curious how you intend to fix this, since we do our best to make sure that wires are broken at pins and junctions inserted. How will you selectively avoid that for schematics that happened to be imported from Eagle?

[Seth Hillbrand (sethh)]

Same as before. We don't break wires unless we are actively adding something to the wire.

I assume the new connectivity algorithm still requires junctions for there to be a connection, right?

[Jon Evans (craftyjon)]

It doesn't care about junctions actually, it just looks at connection points, with labels being a special case. Because wires don't have connection points along their length (just at the end of each segment), they won't form connections along their length except with labels (which have special code to test against segments)

[Seth Hillbrand (sethh)]

OK. That should still work then.

[KiCad Janitor (kicad-janitor)]

Fixed in revision 0b629b4bd434ce0a96e4e9acef720a8695bbb2a8
https://git.launchpad.net/kicad/patch/?id=0b629b4bd434ce0a96e4e9acef720a8695bbb2a8