This derefernce made sense only for explicit paramter passing by reference, but this feature was removed in PHP-7.
The improvement is 100% backward compatible, only few "tricky" functions may be affected (e.g. extract and usort).
array_values():
When the input is an empty array or a packed array with no gaps,
return the original array.
array_keys():
When the input is an empty array, return the original array.
When the input is a packed array with no holes
(and no search key specified), populate the return with
a simple range(0, count($input) - 1)
Hereby, interned strings are supported in thread safe PHP. The patch
implements two types of interned strings
- interning per process, strings are not freed till process end
- interning per request, strings are freed at request end
There is no runtime interning.
With Opcache, all the permanent iterned strings are copied into SHM on
startup, additional copying into SHM might happen on demand.
The reason why we cannot use round() here, is that it does not come with the standard C library on Windows, I don't think this affects other systems.
At the same time, also expose _php_math_round()
Fixes bugs #61967, #62607, #69068, #70713.
The primary changes are:
a) Use the ht_iterator mechanism to ensure safety not only if the
iterated array itself changes, but also if it is replaced (and
potentially destroyed) entirely. We use the same semantics for
behavior under modification as foreach-by-reference. In
particular, we advance to the next element before processing it.
If the iterated entity is exchanged we iterate the new one from
the start. If it is not an array/object we warn and abort.
b) Always create a reference to the current value. Previously the
code kept the value as a non-reference and updated it to the
reference value produced by the user callback. However this is
unsafe, as the array may have been reallocated in the meantime,
so the previous value pointer is no longer value.
c) Around a recursive walk, incref the reference containing the
array. This ensures that the location where the currently
iterated value is stored cannot be freed.
One problem I was not able to solve is that we cannot decrement
the apply count if the array is exchanged during a recursive walk.
