if not char_data then return nil end
local fwidth, pwidth = char_data.width, getwidth(p)
fwidth = fwidth or pwidth
fshift.down = char_data.down; fshift.left = char_data.left
fshift = call_callback("luatexja.set_width", fshift, met, char_data)
local fheight, fdepth = char_data.height, char_data.depth
if not char_data then return nil end
local fwidth, pwidth = char_data.width, getwidth(p)
fwidth = fwidth or pwidth
fshift.down = char_data.down; fshift.left = char_data.left
fshift = call_callback("luatexja.set_width", fshift, met, char_data)
local fheight, fdepth = char_data.height, char_data.depth