Description:
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I define a constant as case-insenstive and then define a capitalization variation of the same constant. In between defines I echo the value of the constant *using the case-sensitive capitalization*.

In the CLI it works as expected, but testing in the apache server gives me the right anser only once, and then a different answers on succesive page reloads. The same happens if instead of echoing I assign the constant value to a variable (e.g. $var = SOME_CONST).

Tested on Chrome, Opera and Firefox, using Apache 2.4.18 Ubuntu.

Steps to reproduce:
* execute the code below, as given, in a web server. You should get (as expected): 12
* reload the page (might need to do this several times) and you get instead: 11

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Other things to note that I tested:

* it works as expected in the command line
* if you don't echo SOME_CONST before defining the case-sensitive variation, it works as expected
* if you echo SOME_const (or any other capitalization variation) there's no bug either
* sometimes it needs one reload and sometimes many (never more than 3 or 4, though)
* after you get the bug, comment the first echo and you'll get the right result again; remove the comment and you get the bug again after few reloads
* if I print the defined constants I see both constants with the right values (namely 1 and 2)

Test script:
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define('sOmE_CoNsT', 1, true);
echo SOME_CONST; // Prints 1

define('SOME_CONST', 2);
echo SOME_CONST; // Prints 2

Expected result:
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Consistently prints "12" on successive page loads

Actual result:
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Prints "12" the first few times, then "11" on successive page reloads