ST_LineSubstring 3D support

[vla123]

It seems that ST_LineSubstring function return wrong results for 3D linestrings.

select 
	st_3dlength(geometry) as full_line ,
	st_3dlength(st_linesubstring(geometry, 0.0, 0.50)) as half_line
from (
		select st_makeline(ARRAY[
		st_setsrid(st_pointz(0,0,0), 3857), 
		st_setsrid(st_pointz(0,2,5), 3857), 
		st_setsrid(st_pointz(0,10,10), 3857)
		]) as geometry
	) line

Output :
  
"full_line"	"half_line"
14.819145939191106	8.92290773165573

This should be explicitly stated on ​documentation.