Bug #77907 [NEW]: mb-functions do not respect default_encoding

From: n dot scheer at binserv dot de Operating system: CentOS 7.6.1810 PHP version: 7.2.17 Package: *Unicode Issues Bug Type: Bug Bug description:mb-functions do not respect default_encoding Description: ------------ The documentation states (c.f. https://www.php.net/manual/en/ini.core.php#ini.default-charset): "In PHP 5.6 onwards, "UTF-8" is the default value and [...] The value of default_charset will also be used to set the default character set for [...] and for mbstring functions if the mbstring.http_input mbstring.http_output mbstring.internal_encoding configuration option is unset." As such, I'd expect to be able to set default_charset to iso-8859-1 and mbstring to pick that same setting for its internal encoding (if the mentioned directives are unset, that is). In the test script below the output of mb_strlen should be "2" in both cases, as iso-8859-1 is a single byte encoding. This is not the case, instead it seems that the two bytes are recognized as the utf-8 character "ö". If mb_internal_encoding is set explicitly, the mb-functions work as expected. But it should in fact not be needed to use mb_internal_encoding() nor the ini setting for it, because default_charset should be used as default. Test script: --------------- <?php ini_set('default_charset', 'iso-8859-1'); var_dump(ini_get("mbstring.internal_encoding")); var_dump(ini_get("mbstring.http_input")); var_dump(ini_get("mbstring.http_output")); var_dump(mb_internal_encoding()); var_dump(mb_strlen( "\xc3\xb6" )); var_dump(mb_strlen( "\xc3\xb6", '8bit' )); mb_internal_encoding('iso-8859-1'); var_dump(mb_internal_encoding()); var_dump(mb_strlen( "\xc3\xb6" )); var_dump(mb_strlen( "\xc3\xb6", '8bit' )); Expected result: ---------------- string(0) "" string(0) "" string(0) "" string(5) "UTF-8" int(1) int(2) string(10) "ISO-8859-1" int(2) int(2) Actual result: -------------- string(0) "" string(0) "" string(0) "" string(5) "UTF-8" int(2) int(2) string(10) "ISO-8859-1" int(2) int(2) -- Edit bug report at https://bugs.php.net/bug.php?id=77907&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=77907&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=77907&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=77907&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=77907&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=77907&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=77907&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=77907&r=needscript Try newer version: https://bugs.php.net/fix.php?id=77907&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=77907&r=support Expected behavior: https://bugs.php.net/fix.php?id=77907&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=77907&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=77907&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=77907&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=77907&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=77907&r=dst IIS Stability: https://bugs.php.net/fix.php?id=77907&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=77907&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=77907&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=77907&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=77907&r=mysqlcfg