php的包含顺序是什么?

.
├── autoload.php
└── etc
    └── php-lib
        ├── autoload.php
        └── common.php

2 directories, 3 files

以及以下内容:

cat autoload.php 
<?php
echo "I am the wrong autoloader";

cat etc/php-lib/autoload.php 
<?php
echo "This is the right one!";

cat etc/php-lib/common.php  
<?php

include_once('autoload.php');

当我跑的时候

$ php etc/php-lib/common.php

我将得到以下输出:

This is the right one!

我之所以这么想,是因为手册规定:

Files are included based on the file path given or, if none is given, the
include_path specified. If the file isn't found in the include_path, 
include will finally check in the calling script's own directory and the 
current working directory before failing. The include construct will emit 
a warning if it cannot find a file; this is different behavior from 
require, which will emit a fatal error. 

I am the wrong autoloader

那为什么是 autoload.php 加载而不是 etc/php-lib/autoload.php ?

事实上,当我分析这个时,include命令似乎比基于手册的预期更奇怪:

第一种情况,上面描述的所有文件都存在

getcwd("/home/hvdb/temp2", 4096)        = 17
lstat("/home/hvdb/temp2/./autoload.php", {st_mode=S_IFREG|0644, st_size=40, ...}) = 0
lstat("/home/hvdb/temp2/autoload.php", {st_mode=S_IFREG|0644, st_size=40, ...}) = 0
openat(AT_FDCWD, "/home/hvdb/temp2/autoload.php", O_RDONLY) = 3

自动加载.php 在cwd里。

./autoload.php 我得到以下信息:

getcwd("/home/hvdb/temp2", 4096)        = 17
lstat("/home/hvdb/temp2/./autoload.php", 0x7fff7f04e880) = -1 ENOENT (No such file or directory)
lstat("/usr/share/php/autoload.php", 0x7fff7f04e880) = -1 ENOENT (No such file or directory)
lstat("/home/hvdb/temp2/etc/php-lib/autoload.php", {st_mode=S_IFREG|0644, st_size=38, ...}) = 0

直到那时我才看到PHP(仍然是首先检查 在cwd中),用于include\u目录中设置的目录,然后用于 autoloader.php