Fix default font chosing when multiple fonts

font_api/init.lua

@@ -44,7 +44,8 @@ function font_api.on_display_update(pos, objref)
 
 	if entity and ndef.display_entities[entity.name] then
 		local def = ndef.display_entities[entity.name]
-		local font = font_api.get_font(meta:get_string("font") or def.font_name)
+		local font = font_api.get_font(meta:get_string("font") ~= ""
+			and meta:get_string("font") or def.font_name)
 
 		local maxlines = def.maxlines or 1 -- TODO:How to do w/o maxlines ?
 

font_api/registry.lua

@@ -49,7 +49,17 @@ local function get_default_font()
 			end
 		end
 
-		-- If failed, choose first font
+		-- If failed, choose first font without default = false
+		if default_font == nil then
+			for _, font in pairs(font_api.registered_fonts) do
+				if font.default then
+					default_font = font
+					break
+				end
+			end
+		end
+
+		-- If failed, chose first font
 		if default_font == nil then
 			for _, font in pairs(font_api.registered_fonts) do
 				default_font = font
@@ -112,6 +122,7 @@ end
 -- If registering different sizes of the same font, add size in the font name
 -- (e.g. times_10, times_12...).
 -- @param def font definition. A associative array with following keys :
+-- @key default True (by default) if this font may be used as default font
 -- @key height (mandatory) Height in pixels of all font textures
 -- @key widths (mandatory) Array of character widths in pixels, indexed by 
 -- UTF codepoints

font_metro/init.lua

@@ -14,6 +14,7 @@
 font_api.register_font(
 	'metro',
 	{
+		default = true,
 		margintop = 3,
 		linespacing = -2,
 		height = 15,