pon., 16 gru 2019 o 10:58 George Peter Banyard <girg...@php.net> napisał(a):
> Greetings internals, > > I'm here to get internals's opinion about allowing a string offset to be > replaced with arbitrary strings. > > Since forever strings with more then one byte have been truncated silently > to one byte. The case with empty string *kinda* was existent but had a > buggy behaviour (see bug 71572 [1]) and as such has been turned into a > warning in PHP 7.1.0, and is meant to be promoted to an Error Exception per > the Reclassifying engine warnings RFC. [2] > An illustration of both these cases is available on 3v4l.org [3] > <https://3v4l.org/O0nEM> > > I've got an implementation ready as a pull request on GitHub [4] (which > still needs some polishing for it to make CI happy and fix the various > leaks). > > However, the question is if this behaviour is desirable. Moreover, the > silent truncation of strings with more than one byte should be changed to > the same severity as the empty string case; i.e. an Error Exception. This > seems reasonable due to the possible loss of data. > > What ever the decision is, a BC break is to be expected. As code which > inadvertently tries to assign multiple bytes to an offset will know have > all those bytes in the string whereas before only the first one was used to > replace the byte at the designated offset. On the other hand the > introduction of an Error Exception is obviously a BC break but as it points > out to some kind of logic error. > I would assume the impact to be minimal for both of these case. > > Any opinions? > > Best regards > > George Peter Banyard > > [1] https://bugs.php.net/bug.php?id=71572 > [2] https://wiki.php.net/rfc/engine_warnings > [3] https://3v4l.org/O0nEM > [4] https://github.com/php/php-src/pull/5013 Allowing to unset string offset with empty string assignment in your patch will not trigger a Warning anymore, but using unset with string offset currently emits "Fatal error: Uncaught Error: Cannot unset string offset". An expected result is to be the same but an effect radically different as you can see [1]. IMHO allowing string offset to be unset using unset construct could be allowed to ensure consistency then. Any thoughts on this? BR, -- Michał Brzuchalski [1] https://3v4l.org/0Ol3N
