Pcbnew - Zone tool does not constrain outline to H, V, 45 Deg when moving corners / edges after initial creation

[Alexander Willer]

Affects Pcbnew.

While the option "Constrain outline to H, V and 45 degrees" in the "Copper Zone Properties" dialogue is honoured during initial zone creation, it has no effect on subsequent modification via dragging of corners / edges.

The expected workflow is, that after laying out the zone roughly, adjustments can be made to achieve the final shape while ensuring the above mentioned constraint. Currently, one must ensure manually, that after dragging, all edges are H, V, or 45 degrees.

If this behaviour is intended in the sense of that the option does only affect initial creation (which seems a bit unintuitive, but could be useful to allow arbitrary modifications after initial zone creation), maybe the Ctrl key should restrict the angles as it already does on graphic line creation (and, more important in this context, also during graphic line modification via dragging).

Application: kicad
Version: 5.1.2-1.fc30, release build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.64.0 OpenSSL/1.1.1c zlib/1.2.11 brotli/1.0.7 libidn2/2.2.0 libpsl/0.20.2 (+libidn2/2.0.5) libssh/0.8.7/openssl/zlib nghttp2/1.38.0
Platform: Linux 5.1.5-300.fc30.x86_64 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: 1.69.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.64.0
    Compiler: GCC 9.0.1 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