[Fontconfig] FcPatternGet always gives font weight of '0'

[Lucien Gentis]

Hello,

My system : Linux Debian 10
fontconfig version : 2.13.1

I have this small code:

#include <stdio.h>
#include <stdlib.h>
#include <X11/Xft/Xft.h>
#include <Xlib.h>
#include <fontconfig.h>

int main(void) {
     Display * display;
     int screen;
     XftFont * font;
     const char * newFont="Liberation Sans:style=Bold Italic";
     FcValue fcValue;

     display=XOpenDisplay(NULL);
     screen = DefaultScreen (display);

     font=XftFontOpenName(display,screen,newFont);

     FcPatternGet(font->pattern,FC_FAMILY,0,&fcValue);
     printf("font family : %s\n",(char *)(fcValue.u.s));
     FcPatternGet(font->pattern,FC_WEIGHT,0,&fcValue);
     printf("font weight : %d\n",fcValue.u.i);
     FcPatternGet(font->pattern,FC_SLANT,0,&fcValue);
     printf("font slant : %d\n",fcValue.u.i);

}


I compile it with command:

gcc -g -Wall -I/usr/include/X11 -I/usr/include/X11/Xft 
-I/usr/include/freetype2 -I/usr/include/fontconfig test.cc -o test -lX11 
-lXft -lfontconfig

If I execute ./test , I get :

font family : Liberation Sans
font weight : 0
font slant : 100

font family and font slant are well displayed, but font weight is always 
to '0' (thin) , whatever weight I choose for 'newFont'.

Additional infos:

--- font "Liberation Sans:style=Bold Italic" is installed - command:
fc-match "Liberation Sans:style=Bold Italic" gives:
LiberationSans-BoldItalic.ttf: "Liberation Sans" "Bold Italic"
--- problem doesn't occur under Linux Ubuntu 18.04 with same version of 
fontconfig