pcbnew, gal: track dragging causes track duplicating

[Sergey A. Borshch]

steps to reproduce:
1) draw track
2) place mouse cursor over track, press "G" hotkey or select track and choose "Drag (free angle)" in drop-down menu
3) move cursor, click to place track end in new location

Expected behavior: track placed to new position.
Actual behavior: new track placed in new position, old track remain on initial position.

Screencast attached.

Version info: today's git head:

Application: Pcbnew
Version: (5.99.0-169-gce62941bb), release build
Libraries:
    wxWidgets 3.0.4
Platform: Linux 5.0.0-23-generic x86_64, 64 bit, Little endian, wxGTK
Build Info:
    Build date: Sep 29 2019 13:17:54
    wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 2.24
    Boost: 1.65.1
    Compiler: GCC 7.4.0 with C++ ABI 1011

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

[Johannes (jos+)]

Noticed same behaviour for

Application: Pcbnew
Version: (5.99.0-221-g39fa3f263-dirty), release build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.58.0 GnuTLS/3.5.18 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 4.15.0-65-generic x86_64, 64 bit, Little endian, wxGTK
Build Info:
    Build date: Oct 12 2019 08:54:43
    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 9.1.0 with C++ ABI 1013

Build settings:
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_PYTHON3=OFF
    KICAD_SCRIPTING_WXPYTHON=ON
    KICAD_SCRIPTING_WXPYTHON_PHOENIX=OFF
    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 4135f0c0e771521efa3f032c9722836d2efecc49
https://git.launchpad.net/kicad/patch/?id=4135f0c0e771521efa3f032c9722836d2efecc49