Doc #68725 [NEW]: Inconsistencies re passing variables by explicit reference

From: ianm at zeweb dot co dot uk Operating system: Linux PHP version: 5.5.20 Package: *General Issues Bug Type: Documentation Problem Bug description:Inconsistencies re passing variables by explicit reference Description: ------------ php 5.4 or later. This concerns inconsistent handling of explicit passing of variables by reference. Some functions permit this when the documentation states that they should not, others the reverse. Examples: mixed preg_replace_callback ( mixed $pattern , callable $callback , mixed $subject [, int $limit = -1 [, int &$count ]] ) mixed str_ireplace ( mixed $search , mixed $replace , mixed $subject [, int &$count ] ) -Which seems to imply that $count SHOULD be passed by explicit reference. In fact, $count is automatically passed by reference, and adding an ampersand will cause a critical error in php 5.4 or later. For these two functions the issue is fixed by removing the ampersand, since the argument is always passed by reference. Quoting the docs on http://php.net/manual/en/language.references.pass.php: "Note: There is no reference sign on a function call - only on function definitions. Function definitions alone are enough to correctly pass the argument by reference. As of PHP 5.3.0, you will get a warning saying that "call-time pass-by-reference" is deprecated when you use & in foo(&$a);. And as of PHP 5.4.0, call-time pass-by-reference was removed, so using it will raise a fatal error." Yet, the documentation on foreach() gives the syntax as: foreach (array_expression as $value) and goes on the say that: "In order to be able to directly modify array elements within the loop precede $value with &. In that case the value will be assigned by reference." -Which seems to be in total violation of the docs! The foreach() issue is harder to overcome since passing by value (removing the ampersand) would not achieve the same result. The worry here is that although (the technically illegal) passing by reference works at present, it may cease to work at some point in the future. There almost certainly are many other examples of such. I understand that the change in php 5.4 -forbidding the passing of variables by explicit reference- was made 'in the interests of consistency' - but I fail to see how this is 'consistent' behaviour. On the contrary, it CREATES major inconsistencies. In principle the whole of the php documentation needs reviewing to find and correct all of these inconsistencies, a very major task. Test script: --------------- foreach ($newusers as &$thisuser){ $username=$thisuser['section_name']; if ($thisuser['privelege']==-1){ $thisuser['is_deleted']=true; continue; } } Expected result: ---------------- Ought to work in 5.3 but should bug-out in 5.4 or later. Actual result: -------------- Works in all tested php versions. The question here is whether it is, or is not, safe to continue using such code? -- Edit bug report at https://bugs.php.net/bug.php?id=68725&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=68725&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=68725&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=68725&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=68725&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=68725&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=68725&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=68725&r=needscript Try newer version: https://bugs.php.net/fix.php?id=68725&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=68725&r=support Expected behavior: https://bugs.php.net/fix.php?id=68725&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=68725&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=68725&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=68725&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=68725&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=68725&r=dst IIS Stability: https://bugs.php.net/fix.php?id=68725&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=68725&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=68725&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=68725&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=68725&r=mysqlcfg