Previously, the unit tests for these text encodings covered all mappings
from legacy -> Unicode, and all _reversible_ mappings from Unicode -> legacy.
However, we should also test the few Unicode -> legacy mappings which
are not reversible.
mbstring had an 'identify filter' for almost every supported text encoding
which was used when auto-detecting the most likely encoding for a string.
It would run over the string and set a 'flag' if it saw anything which
did not appear likely to be the encoding in question.
One problem with this scheme was that encodings which merely appeared
less likely to be the correct one were completely rejected, even if there
was no better candidate. Another problem was that the 'identify filters'
had a huge amount of code duplication with the 'conversion filters'.
Eliminate the identify filters. Instead, when auto-detecting text
encoding, use conversion filters to see whether the input string is valid
in candidate encodings or not. At the same type, watch the type of
codepoints which the string decodes to and mark it as less likely if
non-printable characters (ESC, form feed, bell, etc.) or 'private use
area' codepoints are seen.
Interestingly, one old test case in which JIS text was misidentified
as UTF-8 (and this wrong behavior was enshrined in the test) was 'fixed'
and the JIS string is now auto-detected as JIS.
- Don't allow control characters to appear in the middle of a multi-byte
character. (A strange feature, or perhaps misfeature, of mbstring which is
not present in other libraries such as iconv.)
- When checking whether string is valid, reject kuten codes which do not
map to any character, whether converting from EUC-JP to another encoding,
or converting another encoding which uses JIS X 0208/0212 charsets to
EUC-JP.
- Truncated multi-byte characters are treated as an error.
- Reject otherwise valid kuten codes which don't map to anything in JIS X 0208.
- Handle truncated multi-byte characters as an error.
- Convert Shift-JIS 0x7E to Unicode 0x203E (overline) as recommended by the
Unicode Consortium, and as iconv does.
- Convert Shift-JIS 0x5C to Unicode 0xA5 (yen sign) as recommended by the
Unicode Consortium, and as iconv does.
(NOTE: This will affect PHP scripts which use an internal encoding of
Shift-JIS! PHP assigns a special meaning to 0x5C, the backslash. For example,
it is used for escapes in double-quoted strings. Mapping the Shift-JIS yen
sign to the Unicode yen sign means the yen sign will not be usable for
C escapes in double-quoted strings. Japanese PHP programmers who want to
write their source code in Shift-JIS for some strange reason will have to
use the JIS X 0208 backlash or 'REVERSE SOLIDUS' character for their C
escapes.)
- Convert Unicode 0x5C (backslash) to Shift-JIS 0x815F (reverse solidus).
- Immediately handle error if first Shift-JIS byte is over 0xEF, rather than
waiting to see the next byte. (Previously, the value used was 0xFC, which is
the limit for the 2nd byte and not the 1st byte of a multi-byte character.)
- Don't allow 'control characters' to appear in the middle of a multi-byte
character.
The test case for bug 47399 is now obsolete. That test assumed that a number
of Shift-JIS byte sequences which don't map to any character were 'valid'
(because the byte values were within the legal ranges).
There is no meaningful difference between these and UCS-{2,4}. They are
just a little bit more lax about passing errors silently. They also have
no known use.
Alias to UCS-{2,4} in case someone, somewhere is using them.
Also remove a bogus test (bug62545.phpt) which wrongly assumed that all invalid
characters in CP1251 and CP1252 should map to Unicode 0xFFFD (REPLACEMENT
CHARACTER).
mbstring has an interface to specify what invalid characters should be
replaced with; it's called `mb_substitute_character`. If a user wants to see
the Unicode 'replacement character', they can specify that using
`mb_substitute_character`. But if they specify something else, we should
follow that.
mb_ereg()/mb_eregi() currently have an inconsistent return value
based on whether the $matches parameter is passed or not:
> Returns the byte length of the matched string if a match for
> pattern was found in string, or FALSE if no matches were found
> or an error occurred.
>
> If the optional parameter regs was not passed or the length of
> the matched string is 0, this function returns 1.
Coupling this behavior to the $matches parameter doesn't make sense
-- we know the match length either way, there is no technical
reason to distinguish them. However, returning the match length
is not particularly useful either, especially due to the need to
convert 0-length into 1-length to satisfy "truthy" checks. We
could always return 1, which would kind of match the behavior of
preg_match() -- however, preg_match() actually returns the number
of matches, which is 0 or 1 for preg_match(), while false signals
an error. However, mb_ereg() returns false both for no match and
for an error. This would result in an odd 1|false return value.
The patch canonicalizes mb_ereg() to always return a boolean,
where true indicates a match and false indicates no match or error.
This also matches the behavior of the mb_ereg_match() and
mb_ereg_search() functions.
This fixes the default value integrity violation in PHP 8.
Closes GH-6331.
There was one faulty test in the suite which only passed before because UTF-16 had no
identify filter. After this was fixed, it exposed the problem with the test.
Man, I can be pedantic sometimes. Tiny little things like misspelled words just
hurt me inside. So while it's not really a big deal, I couldn't leave these typos
alone...
Don't expose references in debug_backtrace() or exception traces.
This is regardless of whether the argument is by-reference or not.
As a side-effect of this change, exception traces may now acquire
the interior value of a reference, which may be unexpected for
some internal functions. This is what necessitated the change in
the spl_array sort implementation.
From now on, we always display the given object's type instead of just reporting "object".
Additionally, make the format of return type errors match the format of argument errors.
Closes GH-5625
