Jade: block statement in included components

comp1.jade

block append test
	h1 from comp1

comp2.jade

block append test
	h1 from comp2

layout.jade

block test
	p begin of test
	h1 from layout
block main
	p from layout

node-jade.html

<p>begin of test</p>
<h1>from layout</h1>
<h2>from comp2</h2>
<h1>from comp1</h1>
<h2>from view</h2>
<p>beging of main</p>
<h1>from comp1</h1>
<h2>from view</h2>
<h2>from comp2</h2>
<h1>from comp1</h1>
<h2>from view</h2>
<p>end of main</p>

php-jade.php

<p>begin of test</p>
<h1>from layout</h1>
<h2>from view</h2>
<p>beging of main</p>
<h1>from comp1</h1>
<h2>from view</h2>
<h2>from comp2</h2>
<h2>from view</h2>
<p>end of main</p>

view.jade

extends layout

block append test
	h2 from view

block main
	p beging of main
	include comp1
	include comp2
	p end of main

Using block in include jade file is undefined behavior, according to the spec(or introduction) in jade-lang.

In jade1.9, content in block append ... section appears in the corresponding block section in layout, and at the same time appears immediately after the block append section.

In previous Jade(personally I tested 1.5) and php dialect, content in block append ... only appears at where it is defined but not inserted into its corresponding block section in layout.