Dimension unit change imprecise

[Patrik Bachan]

This report extends secondary problem discovered in bug #1853690.

See attached video. I am using 1mm grid, project default dimension unit is set to inches.

TL-DW:
- Have default dimension set to inches, use metric grid
- create dimension
- edit dimension to switch units from inches to mm
- value of dimension is not aligned with grid eg.: 7.00024 mm instead of 7 mm

I don't really know cause of this. Value of dimension is converted with an numeric error. Once you try to move end of dimension, value gets recalculated to correct one.

It's same thing when you create mm dimension on inch grid and then switch unit to inches. There is an conversion error.

Application: Pcbnew
Version: (5.99.0-402-g13df645af), release build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.67.0 OpenSSL/1.1.1d zlib/1.2.11 libidn2/2.3.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh2/1.9.0 nghttp2/1.39.2
Platform: Linux 5.3.11-arch1-1 x86_64, 64 bit, Little endian, wxGTK
Build Info:
    Build date: Nov 22 2019 22:00:56
    wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
    Boost: 1.71.0
    OpenCASCADE Technology: 7.4.0
    Curl: 7.67.0
    Compiler: GCC 9.2.0 with C++ ABI 1013

Build settings:
    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=OFF
    KICAD_USE_OCC=ON
    KICAD_SPICE=ON

[KiCad Janitor (kicad-janitor)]

Fixed in revision 9f9b48739c9e72c81f675454945a3620755f11ae
https://git.launchpad.net/kicad/patch/?id=9f9b48739c9e72c81f675454945a3620755f11ae