Edit report at https://bugs.php.net/bug.php?id=49664&edit=1
ID: 49664 Comment by: kurt at kurtrose dot com Reported by: patrik dot lermon at gmail dot com Summary: Clone causes Segmentation fault Status: Not a bug Type: Bug Package: Reproducible crash Operating System: Linux PHP Version: 5.*, 6 (2009-09-20) Block user comment: N Private report: N New Comment: Python handles this kind of recursion fine: class F(object): def __repr__(self): return self.__repr__() >>> repr(F()) File "<stdin>", line 2, in __repr__ File "<stdin>", line 2, in __repr__ ... File "<stdin>", line 2, in __repr__ File "<stdin>", line 2, in __repr__ RuntimeError: maximum recursion depth exceeded No segfault. Previous Comments: ------------------------------------------------------------------------ [2009-10-19 15:31:17] patrik dot lermon at gmail dot com I don't agree. Perhaps my knowledge is not detailed enough, but an infinte recursion should: a) run out of memory and die, or b) detect the recursion and die. In both these cases PHP should die in a controlled manner, not segfault. My understanding is that segfault is never ok - that means the code is faulty. ------------------------------------------------------------------------ [2009-10-19 15:10:24] j...@php.net Infinite recursion crashes. There's no fix for that. ------------------------------------------------------------------------ [2009-09-28 12:06:43] patrik dot lermon at gmail dot com I get the same result with http://snaps.php.net/php5.3-latest.tar.gz on Slackware. ------------------------------------------------------------------------ [2009-09-25 07:50:31] patrik dot lermon at gmail dot com I am aware that the cloning will be recursive in some circumstances, but PHP should not segfault because of this. ------------------------------------------------------------------------ [2009-09-25 07:46:10] patrik dot lermon at gmail dot com Description: ------------ Under certain circumstances the clone keyword causes a Segmentation fault. This code is reproducible and tested with the same result on: - Ubuntu 9.04 / PHP 5.2.10 (cli) (built: Jun 22 2009 12:32:02) - Slackware 13.0.0.0.0 / PHP 5.3.0 (cli) (built: Sep 25 2009 08:58:26) (DEBUG) - Mac OS X 10.5.8 / PHP 5.2.10 (cli) (built: Aug 24 2009 12:47:12) - Mac OS X 10.6.1 / PHP 5.3.0 (cli) (built: Jul 19 2009 00:34:29) The Ubuntu and Mac OS X versions are standard builds from Zend, and the Slackware is built by me like this: EXTENSION_DIR=/usr/lib/php/extensions \ CFLAGS="-O2 -march=i486 -mtune=i686" \ ./configure \ --enable-force-cgi-redirect \ --enable-pcntl \ --enable-sigchild \ --prefix=/usr \ --libdir=/usr/lib \ --with-libdir=lib \ --sysconfdir=/etc \ --disable-safe-mode \ --disable-magic-quotes \ --enable-zend-multibyte \ --enable-mbregex \ --enable-tokenizer=shared \ --with-config-file-scan-dir=/etc/php \ --with-config-file-path=/etc/httpd \ --enable-mod_charset \ --with-layout=PHP \ --enable-sigchild \ --enable-xml \ --with-libxml-dir=/usr \ --enable-simplexml \ --enable-spl \ --enable-filter \ --enable-debug \ --with-openssl=shared \ --with-pcre-regex=/usr \ --with-zlib=shared,/usr \ --enable-bcmath=shared \ --with-bz2=shared,/usr \ --enable-calendar=shared \ --enable-ctype=shared \ --with-curl=shared \ --with-curlwrappers \ --with-mcrypt=/usr \ --enable-dba=shared \ --with-gdbm=/usr \ --with-db4=/usr \ --enable-exif=shared \ --enable-ftp=shared \ --with-gd=shared \ --with-jpeg-dir=/usr \ --with-png-dir=/usr \ --with-zlib-dir=/usr \ --with-xpm-dir=/usr \ --with-freetype-dir=/usr \ --with-t1lib=/usr \ --enable-gd-native-ttf \ --enable-gd-jis-conv \ --with-gettext=shared,/usr \ --with-gmp=shared,/usr \ --with-iconv=shared \ --with-imap-ssl=/usr \ --with-imap=/usr/local/lib/c-client \ --with-ldap=shared \ --enable-mbstring=shared \ --enable-hash \ --with-mysql=shared,/usr \ --with-mysqli=shared,/usr/bin/mysql_config \ --enable-pdo=shared \ --with-pdo-mysql=shared,/usr \ --with-pdo-sqlite=shared \ --with-pspell=shared,/usr \ --with-mm=/usr \ --enable-shmop=shared \ --with-snmp=shared,/usr \ --enable-soap=shared \ --enable-sockets \ --with-sqlite=shared \ --enable-sqlite-utf8 \ --with-regex=php \ --enable-sysvmsg \ --enable-sysvsem \ --enable-sysvshm \ --enable-wddx=shared \ --with-xsl=shared,/usr \ --enable-zip=shared \ --with-tsrm-pthreads \ --enable-shared=yes \ --enable-static=no \ --with-gnu-ld \ --with-pic \ --build=i486-slackware-linux Reproduce code: --------------- <?php date_default_timezone_set('America/Los_Angeles'); class Test { public $previous, $next = NULL; public function __clone() { $this->previous != NULL ? $this->previous = clone $this->previous : $this->previous = NULL; $this->next != NULL ? $this->next = clone $this->next : $this->next = NULL; } public function __toString() { return '[' . ($this->previous != NULL ? '<' : '-') . ' ' . ($this->next != NULL ? '>' : '-') . ']'; } } // Create some test objects $a = new Test(); $b = new Test(); // Link them together $a->next =& $b; $b->previous =& $a; // Clone and print echo "a before cloning:\na: " . $a . "\n"; $b = clone $a; echo "These two should not look the same:\na: " . $a . "\nb: " . $clone . "\n"; Expected result: ---------------- a before cloning: a: [- >] These two should not look the same: a: [- >] b: [- -] Actual result: -------------- a before cloning: a: [- >] Segmentation fault ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=49664&edit=1
