Instead of returning the encoding of the current substitution
character. This allows a robust check for the failure case. The
substitution character (especially the default of "?") is also
a valid output of mb_chr() for a valid input (for "?" that would be
0x3f), so it's a bad choice for an error value.
Previously mb_chr() had two different encoding-dependent behaviors:
* For "Unicode-encodings" it took a Unicode codepoint and returned
its encoded representation.
* Otherwise it returned a big-endian binary encoding of the passed
integer.
Now the input is always interpreted as a Unicode codepoint. If
a big-endian binary encoding is what you want, you don't need
mbstring to implement that.
The introduced checks were not correct in two respects:
* It was checked whether the source encoding of the string matches
the internal encoding, while the actually relevant encoding is
the *target* encoding.
* Even if the correct encoding is used, the checks are still too
conservative. Just because something is not a "Unicode-encoding"
does not mean that it does not map any non-ASCII characters.
I've reverted the added checks and instead adjusted mbfl_convert
to first try to use the provided substitution character and if
that fails, perform the fallback to '?' at that point. This means
that any codepoint mapped in the target encoding should now be
correctly supported and anything else should fall back to '?'.
The introduced checks did not treat "non-Unicode" encodings correctly,
because they treated the passed integer as encoded in the internal
encoding in that case, while in actuality the substitute character
is always a Unicode codepoint.
Additionally checking the codepoint against the internal encoding
is not correct in any case, because the substitution character must
be mapped in the *target* encoding of the conversion, which does
not necessarily coincide with the internal encoding (the internal
encoding is the default *source* encoding, not *target* encoding).
This reverts the checks back to simple range checks, but in a way
that still resolves#69079: Characters outside the Basic
Multilingual Plane are now accepted and Surrogate Codepoints are
rejected. A distinction between UTF-8 and non-UTF-8 encodings is
not made for surrogate checks (as in the original patch), as
surrogates are always illegal on their own. Specifying a surrogate
as substitution character would only make sense if you could
specify a substitution string with more than one character --
however we do not support that.
spl_object_id is a new function returning the object handle,
as a signed integer.
Discussion for this new function is ongoing on php-internals, see
https://marc.info/?t=143835274500003&r=1&w=2
The object id is unique for the lifetime of the object.
When the object is garbage collected,
different objects may & will have the same object id.
- This is also the case for the string generated by spl_object_hash
It is always possible to cast the object handle to a **signed** zend_long
in php 7.2. _zend_object->handle is always of the type `uint32_t`.
(zend_long is 32 bits on 32 bit builds, 64 bits on 64 bit builds)
As of php 7.0, the object id uniquely identifies the object,
there can't be two objects with the same id but different handlers
(See the implementation of spl_object_hash)
Skip the pointless XORing, as discussed in internals.
- It was intended to avoid exposing in-memory addresses.
- The object handle is not a memory address.
- The output of var_dump() includes the object handle(id)
