Comment 0 for bug 1828824

Tested on commit 92ccb766ab197157bba3c545cc721e7f20e46d2e.

If you drag a triangle vertex in order to change its size, after some time an "assert" is issued.

How to reproduce:

-Create a new symbol
-Insert a rectangle
-Select the rectancle and drag one vertex.
-After some drawing with a "flashing" rectangle you get:

"An assertion failed"
...kicad/common/gal/opengl/gpu_manager.cpp(119): assert "m_isDrawing" failed in DrawIndices().

and in backtrace box, under the "Function prototype" you get:
make_fcontext

Then the assert window, clicking on "continue" is shown some more time.

P.S.: Dragging a circles cotrol point seems to work correctly.

Cheers,
Dino Ghilardi.

---------------------------------
Application: kicad
Version: (5.1.0-550-g92ccb766a), debug build
Libraries:
    wxWidgets 3.0.2
    libcurl/7.52.1 OpenSSL/1.0.2r zlib/1.2.8 libidn2/0.16 libpsl/0.17.0 (+libidn2/0.16) libssh2/1.7.0 nghttp2/1.18.1 librtmp/2.3
Platform: Linux 4.9.0-8-amd64 x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.0.2 (wchar_t,wx containers,compatible with 2.8) GTK+ 2.24
    Boost: 1.69.0
    OpenCASCADE Community Edition: 6.8.0
    Curl: 7.52.1
    Compiler: GCC 6.3.0 with C++ ABI 1010

Build settings:
    USE_WX_GRAPHICS_CONTEXT=OFF
    USE_WX_OVERLAY=OFF
    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