thinkphp (3.2.1), write the source code a little bit of a problem. About the absolute address.

In accordance with the official source code, I knocked over the control. Just started knocking. I found a little problem.
First I wrote that thinkphp.php is the public entrance file.

 // +----------------------------------------------------------------------//----------------------------------// thinkphp Public Entry File//----------------------------------//Record start run time $globals[' _begintime '] = Microtime (TRUE);// Record memory initial use define (' memory_limit_on ', function_exists (' memory_get_usage ')); if (memory_limit_on) $GLOBALS [' _  Startusemems '] = Memory_get_usage ();//version information const Think_version = ' 3.2.1 ';//URL pattern definition Const URL_COMMON = 0;  Normal Mode Const URL_PATHINFO = 1;  PathInfo Mode const URL_REWRITE = 2;  Rewrite mode const URL_COMPAT = 3; Compatibility mode//class file suffix const EXT = '. class.php '; System constants define defined (' Think_path ') or define (' Think_path ', __dir__. ') /'), Echo think_path;defined (' App_path ') or define (' App_path ', dirname ($_server[' script_filename ']). ' /');d efined (' app_status ') or define (' app_status ', '); Apply state to load the corresponding configuration file defined (' App_debug ') or define (' App_debug ', false); Whether debug mode if (Function_exists (' Saeautoloader ')) {//auto-Identify SAE environment defineD (' App_mode ') or define (' App_mode ', ' SAE '); Defined (' Storage_type ') or define (' Storage_type ', ' Sae ');} else{defined (' App_mode ') or define (' App_mode ', ' common ');//Application Mode defaults to normal mode defined (' Storage_type ') or Define (' Storage_type ', ' File ');   The storage type defaults to file}defined (' Runtime_path ') or define (' Runtime_path ', App_path. ' runtime/'); System runtime directory defined (' Lib_path ') or define (' Lib_path ', Realpath (think_path. ' Library '). ' /'); System Core Class Library Directory

That's the line. Defines a constant lib_path. There was a problem. I first output think_path (35th line definition), output "d:\wamp\www\bbbb\thinkphp/" but when the constants are appended to the library, and then the Realpath function parsing, it will not be parsed, only the most back of the "/"。
Then I found the framework of the thinkphp, the source code, and then the public entrance file echo a bit, no problem.
However, when I directly copy this public access file to a new file, I get the same error. May I ask why this is?
There may be some confusion, I hope you don't mind.

Reply to discussion (solution)

Not sure enough, don't modify the core code of the framework
When using frames, do not change any files outside of the file that allows you to modify

Not sure enough, don't modify the core code of the framework
When using frames, do not change any files outside of the files that allow you to modify them. Just to understand his process. Think about his theory. I did it alone and didn't use him for work.

I have this problem, too.

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