2009/8/22 Szczepan Hołyszewski <webmaster@xxxxxxxxxxxxxx>:
>> What it looks like to me is that something is causing $foo to be a
>> string before the '$foo[] = "bar";' line is encountered. What do you
>> get if you put a gettype($foo); just before that line?
>>
>> > $foo=null;
>> > $foo[]="bar"; // <-- $foo simply becomes an array
>
> NULL. That is the problem. I _did_ put a gettype($foo) before the actual line.
>
> OK, here are exact four lines of my code:
>
> $ret=array();
> foreach(self::$_allowed as $r => $a)
> if ($a)
> $ret[]=$r;
>
> As you can see, there is not a shred of a chance for $ret to become something
> other than empty array between initialization and the last line in the above
> snippet which causes the fatal errror. There's no __staticGet in 5.2.9, so
> self::$_allowed cannot have side effects.
>
> Secondly, the above code starts failing after it has executed successfully
> dozens of times (and yes, the last line _does_ get executed; in fact self::
> $_allowed contains configuration information that doesn't change at runtime).
>
> Thirdly...
>
>> > The problem is not limited to one place in code, and indeed before the
>> > fatal caused by append-assignment I get several warnings like
>> > "array_diff_key(): Argument #1 is not an array", where the offending
>> > argument receives a result of array().
>>
>> This would appear to support my suspicion, but try inserting the
>> gettype($foo) (or better, var_export($foo);) just before one of the
>> lines which triggers the error, and post the results.
>
> No, I don't think it supports your suspicion. Conversely, it indicates that
> once array() returns a strangelet, it starts returning strangelets all over
> the place. Initially it only triggers warnings but eventually one of the
> returned strangelets is used in a way that triggers a fatal error.
>
> As per your request:
>
> //at the beginning of the script:
>
> $GLOBALS['offending_line_execution_count']=0;
>
> // /srv/home/[munged]/public_html/scripts/common.php line 161 and on
> // instrumented as per your request:
>
> public static function GetAllowed() {
>
> if (debug_mode()) echo ++$GLOBALS['offending_line_execution_count']."<br/>";
> $ret=array();
> if (debug_mode()) echo var_export($ret)."<br/>";
> foreach(self::$_allowed as $r => $a)
> if ($a)
> $ret[]=$r;
>
> if (self::$_allowEmpty) $ret[]="";
> return $ret;
> }
>
> Output tail:
> -----------------------------------------------
> 28
> array ( )
> 29
> array ( )
> 30
> array ( )
> 31
> array ( )
> 32
> array ( )
>
> Warning: array_diff_key() [function.array-diff-key]: Argument #1 is not an array
> in /srv/home/u80959ue/public_html/v3/scripts/SimpliciText.php on line 350
>
> Warning: Invalid argument supplied for foreach() in
> /srv/home/u80959ue/public_html/v3/scripts/SimpliciText.php on line 351
>
> Warning: array_merge() [function.array-merge]: Argument #2 is not an array in
> /srv/home/u80959ue/public_html/v3/scripts/SimpliciText.php on line 357
>
> Warning: Invalid argument supplied for foreach() in
> /srv/home/u80959ue/public_html/scripts/common.php on line 28
>
> Warning: Invalid argument supplied for foreach() in
> /srv/home/u80959ue/public_html/scripts/common.php on line 28
>
> Warning: Invalid argument supplied for foreach() in
> /srv/home/u80959ue/public_html/scripts/common.php on line 28
> 33
> NULL
>
> Fatal error: [] operator not supported for strings in
> /srv/home/u80959ue/public_html/scripts/common.php on line 168
> --------------------------------------------------
>
> The warnings come from other uses of array().
>
> But wait! There is this invocation of debug_mode() between initialization of
> $ret var_export. Let's factor it out to be safe:
>
> $debugmode=debug_mode();
> if ($debugmode) echo ++$GLOBALS['offending_line_execution_count']."<br/>";
> $ret=array();
> if ($debugmode) echo var_export($ret)."<br/>";
>
> And now the output ends with:
>
> ------------------------------------
> Warning: Invalid argument supplied for foreach() in
> /srv/home/u80959ue/public_html/scripts/common.php on line 28
> 33
>
> Fatal error: [] operator not supported for strings in
> /srv/home/u80959ue/public_html/scripts/common.php on line 169
> ------------------------------------
>
> No NULL after 33? What the heck is going on? Does array() now return something
> that var_exports to an empty string, or does it destroy local variables? Let's
> see:
>
> if ($debugmode) echo var_export($ret)."<br/>"; else echo "WTF?!?!?<br/>";
>
> And the output:
> ------------------------------------
> Warning: Invalid argument supplied for foreach() in
> /srv/home/u80959ue/public_html/scripts/common.php on line 28
> 33
> WTF?!?!?
>
> Fatal error: [] operator not supported for strings in
> /srv/home/u80959ue/public_html/scripts/common.php on line 169
> ---------------------------------------
>
> Indeed, the use of array(), once it starts misbehaving, wreaks havoc in the
> local scope (possibly including the variable to which its result is assigned).
>
>> Can you post the code in a .zip file or online somewhere?
>
> Unfortunately not.
>
> Szczepan Holyszewski
Hm. . .it does look odd. Searching the bugs database at
http://bugs.php.net does turn up one other report (at
http://bugs.php.net/bug.php?id=47870 ) of array() returning NULL in
certain hard-to-duplicate circumstances on FreeBSD, although it's a
different version of FreeBSD and is reported against
5.3CVS-2009-04-01. There are differences but the similarities are
suspicious. That particular bug was fixed but if this does in fact
turn out to be a bug in PHP then the ability to test other versions
would be very useful. Too bad about the shared host. I know how hard
it can be to get them to install other versions, even if just for
testing.
I don't suppose you have a development environment on another machine
where you can test another version of PHP? If not, it's going to be
slightly difficult to pin down.
It may be worth it for you to add a comment to the above bug report.
The current 5.2 is only at 5.2.10 so the version you're using isn't
very old, and a fix for this problem is not specifically mentioned in
the PHP 5.2.10 changelog.
Good luck!
Torben
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