Re: [Dev-luatex] used_font always return false

On 17 September 2019 14:56:20 CEST, luigi scarso wrote:

On Tue, Sep 17, 2019 at 2:52 PM Marcel Fabian Krüger wrote:

...

Hi,

the node(.direct).uses_font helpers currently always return false for glyph nodes: In the implementation

static int lua_nodelib_direct_uses_font(lua_State * L) { halfword n = lua_tointeger(L,1); halfword f = lua_tointeger(L,2); halfword p; if (type(n) == glyph_node) { lua_pushboolean(L,font(n) == f); } else if (type(n) == disc_node) { uses_font_disc(pre_break,p,n); uses_font_disc(post_break,p,n); uses_font_disc(no_break,p,n); } /* todo: other node types */ lua_pushboolean(L,0); return 1; }

the actual result is first calculated, but then the last pushboolean pushes a `false` on top of the stack and return this false. It could e.g. be fixed by adding a `return 1;` at the end of the first if block. `disc` nodes are not affected because uses_font_disc is a macro containing `return`.

A minimal example in plain LuaTeX:

\directlua{ local g = node.new'glyph' g.font = font.current() if not node.uses_font(g, font.current()) then error'This should not happen' end node.free(g) } \bye

hm, probably a missed else, ie

} else { /* todo: other node types */ lua_pushboolean(L,0); }

That wouldn't quite work because the uses_font_disc code only returns if the result is true, so pushboolean would also be needed in the disc case.