Edit report at https://bugs.php.net/bug.php?id=55493&edit=1

 ID:                 55493
 Updated by:         ka...@php.net
 Reported by:        vovan-ve at yandex dot ru
 Summary:            Superglobal variable variables with ${expression} in
                     non-global scope
-Status:             Wont fix
+Status:             Assigned
-Type:               Bug
+Type:               Feature/Change Request
 Package:            Variables related
 Operating System:   Windows XP SP3
 PHP Version:        5.3.7
-Assigned To:        
+Assigned To:        dmitry
 Block user comment: N
 Private report:     N

 New Comment:

This still seems a little strange that we cannot pick the correct symbol table 
at compile time, all it should need would be a check to see if the compiled 
value is matching one thats a super global.

I remember to have encountered something similar a while back, which I'm not 
sure if I reported or not, but def. something we should look into at some point.

Dmitry, can you clarify this?


Previous Comments:
------------------------------------------------------------------------
[2011-08-23 16:49:00] larue...@php.net

As I said, this is a limitation of PHP design, so mark as won't fix. 
Thank you for your interest in PHP.

------------------------------------------------------------------------
[2011-08-23 16:22:46] larue...@php.net

when fetching a variable, the target symbol table is decided in compiling time, 
 
for the script above,  in compiling time, only const string "_SERVER" can be 
took consider as a SUPERVAR and assign the global symbol table as 
target_symbol_table.

the others `varname` only can be see in execution time, so Zend VM think it 
should be fetched from a local symbol table.

and the 'local symbol table' for the global scope statement is actual 'global 
symbol table', therefor it works 'as expected'.

------------------------------------------------------------------------
[2011-08-23 14:14:42] vovan-ve at yandex dot ru

Description:
------------
ONLY Superglobal variable variables does not work ONLY in non-global
scope and ONLY with non-constant expression. See test script.

I found Req 38527, but it does not describe the problem properly and
due to misunderstanding it has status Feature Request instead of Bug
(and also it is too old).

Test script:
---------------
// in global scope everything is right
$name = '_SERVER';
var_dump(
    isset(${'_SERVER'}),
    isset($$name),
    isset(${$name}),
    isset(${'_SER' . 'VER'}),
    isset(${'na' . 'me'})
);
echo PHP_EOL;

// but outside of global scope there is a trouble
function f() {
    $name = '_SERVER';
    var_dump(
        isset(${'_SERVER'}),
        isset($$name),
        isset(${$name}),
        isset(${'_SER' . 'VER'}),
        isset(${'na' . 'me'})
    );
}
f();

Expected result:
----------------
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)

bool(true)
bool(true)
bool(true)
bool(true)
bool(true)

Actual result:
--------------
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)

bool(true)
bool(false)
bool(false)
bool(false)
bool(true)


------------------------------------------------------------------------



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