pad with custom shape : the solder mask is badly plotted if its minimum value isn't null.

[syl20j]

Application: kicad
Version: (5.0.0), release build
Libraries:
    wxWidgets 3.0.3
    libcurl/7.54.1 OpenSSL/1.0.2l zlib/1.2.11 libssh2/1.8.0 nghttp2/1.23.1 librtmp/2.3
Platform: Windows 8 (build 9200), 64-bit edition, 64 bit, Little endian, wxMSW
Build Info:
    wxWidgets: 3.0.3 (wchar_t,wx containers,compatible with 2.8)
    Boost: 1.60.0
    OpenCASCADE Community Edition: 6.8.0
    Curl: 7.54.1
    Compiler: GCC 7.1.0 with C++ ABI 1011

Build settings:
    USE_WX_GRAPHICS_CONTEXT=OFF
    USE_WX_OVERLAY=OFF
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_WXPYTHON=ON
    KICAD_SCRIPTING_ACTION_MENU=OFF
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON

In the example file joined hereafter, the Gerber file of the solder mask is badly plotted : the solder mask clearance of the pads with a custom shape is 0mm while the parameters in Pcbnew are 0.075mm for the solder mask clearance and 0.1mm for the solder mask min width.
If the solder mask min width = 0mm in Pcbnew, then the solder mask clearance plotted in gerber is equal to the solder mask clearance in Pcbnew (correct behavior).

In the example, from left to rigth :
QFN50P350X350-16T214 - footprint with custom shape (rectangular anchor with ring primitive),
QFN50P350X350-16T214_2 - footprint with custom shape (circular anchor with polygon primitive)
QFN50P350X350-16T214_3 - footprint with rectangular shape,
QFN50P350X350-16T214_4 - footprint with rounded rectangular shape

[KiCad Janitor (kicad-janitor)]

Fixed in revision 619e13dc2d38aed2220d52b5a760204835a3847b
https://git.launchpad.net/kicad/patch/?id=619e13dc2d38aed2220d52b5a760204835a3847b