Bug #80652 [NEW]: Regex delimiters not validated correctly

From: greg at subaqua dot co dot uk Operating system: n/a PHP version: Irrelevant Package: PCRE related Bug Type: Bug Bug description:Regex delimiters not validated correctly Description: ------------ The documentation at https://www.php.net/manual/en/regexp.reference.delimiters.php says that: When using the PCRE functions, it is required that the pattern is enclosed by delimiters. A delimiter can be any non-alphanumeric, non-backslash, non-whitespace character. The validation for delimiters works in *most* cases and gives a warning such as: Warning: preg_split(): Delimiter must not be alphanumeric or backslash in php shell code on line 1 However, it fails to detect the invalid delimiters in the string " *, *". Instead, it runs without error/warning and gives output based on a substring(?) of the supplied regex. According to https://3v4l.org/DdBp1 it affects all versions of PHP from 4.3 to 8.0 Test script: --------------- # Valid delimiters - PASS php > var_export(preg_split('/ *, */', 'a , b')); array ( 0 => 'a', 1 => 'b', ) # Invalid delimiters - PASS - gives warning as expected php > var_dump(preg_split('X *, *Y', 'a , b')); Warning: preg_split(): Delimiter must not be alphanumeric or backslash in php shell code on line 1 bool(false) # Invalid delimiters - FAIL - should warn about either mismatched or invalid delimiters. # Instead, it gives no warning and unexpected output. php > var_export(preg_split(' *, *', 'a , b')); array ( 0 => 'a ', 1 => 'b', ) Expected result: ---------------- I expect the invalid delimiters to trigger a warning. Actual result: -------------- The invalid delimiters are silently ignored. The output does not correspond to the supplied regex. -- Edit bug report at https://bugs.php.net/bug.php?id=80652&edit=1 -- Fix committed: https://bugs.php.net/fix.php?id=80652&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=80652&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=80652&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=80652&r=needscript Try newer version: https://bugs.php.net/fix.php?id=80652&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=80652&r=support Expected behavior: https://bugs.php.net/fix.php?id=80652&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=80652&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=80652&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=80652&r=globals PHP version support discontinued: https://bugs.php.net/fix.php?id=80652&r=phptooold Daylight Savings: https://bugs.php.net/fix.php?id=80652&r=dst IIS Stability: https://bugs.php.net/fix.php?id=80652&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=80652&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=80652&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=80652&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=80652&r=mysqlcfg