[PHP-DEV] Bug #11218 Updated: isset() inside for() loops can crash
ID: 11218
User Update by: [EMAIL PROTECTED]
Old-Status: Feedback
Status: Open
Bug Type: Scripting Engine problem
Operating system: NT 4.0 SP6a
PHP Version: 4.0.5
Description: isset() inside for() loops can crash
Tested latest snapshot, http://www.zend.com/snapshots/get_latest.php, as of 17:00
-400. The problem with isset() inside for loops is fixed. BUT, there is still a
problem. Testing a multidimensional array when only one dimension of the array is set
causes the test to come out true even when it is not. See example:
http://bugs.php.net/?id=11218
#
# This "if isset()" test comes out as true
# even though it's actually false.
echo 'Should not see anything else after this...';
$Var['SC'] = 'y';
if ( isset($Var['SC']['hide']) ) {
echo "isset() says \$Var['SC']['hide'] is set.";
}
?>
PS: I'm saddened to hear new versions of PHP are going out with unresolved bugs in
functions as basic and essential as isset().
Previous Comments:
---
[2001-06-21 12:14:07] [EMAIL PROTECTED]
I was unable to reproduce that problem, however, I did fix bug #10911 which appears to
be based on the same issue. Can you please test the latest CVS and see whether it
solves your problem (note, this fix may not be a part of 4.0.6, since 4.0.6 has
already been packaged; It'll definitely be in 4.0.7)
---
[2001-06-05 17:20:08] [EMAIL PROTECTED]
Bug 10911, http://www.php.net/bugs.php?id=10911, was brought to my attention. Both my
report above and this other one may be based on the same bug.
---
[2001-05-31 12:33:40] [EMAIL PROTECTED]
in for ';
if ( isset($Col['SC']['hide']) ) {
echo 'in if';
}
}
}
Test(__FILE__,__LINE__);
# NOW, funny things happen if I change the number of times
# the for loop runs...
# $Counter < 1...
# Everything is fine.
# $Counter < 2...
# Dr Watson notifys of PHP crash, hit OK
# (SeeDr Watson report at end of this posting.)
# Text is displayed in browser.
# PHP no longer running.
# $Counter < 3...
# Nothing returned to browser.
# No Dr Watson reports.
# PHP won't stop executing, takes up 99% of processor time.
# Can't "End Process" in Task Manger.
# Doesn't stop after max execution time.
# Need to reboot to kill PHP process.
#
# Though, if I execute from command line...
# winds up in same infinite loop, but I can
# kill the PHP process from the task manager.
# So, if that's not strange enough, altering the
# test code in small ways eliminates the problem...
# remove if / isset segment...
# okay
/*
function Test($FileName, $FileLine, $Opt='', $Col='') {
for ($Counter = 0; $Counter < 3; $Counter++) {
echo 'in for ';
}
}
Test(__FILE__,__LINE__);
*/
# put the if / isset segment back
# BUT remove the for loop
# okay
/*
function Test($FileName, $FileLine, $Opt='', $Col='') {
if ( isset($Col['SC']['hide']) ) {
echo 'in if';
}
}
Test(__FILE__,__LINE__);
*/
# put the for loop back
# BUT do isset on a single dimensional array...
# okay
/*
function Test($FileName, $FileLine, $Opt='', $Col='') {
for ($Counter = 0; $Counter < 3; $Counter++) {
echo 'in for ';
if ( isset($Col['SC']) ) {
echo 'in if';
}
}
}
Test(__FILE__,__LINE__);
*/
# perform tasks outside a function.
# okay
/*
for ($Counter = 0; $Counter < 3; $Counter++) {
echo 'in for ';
if ( isset($Col['SC']['hide']) ) {
echo 'in if';
}
}
*/
# set the array before running function
# okay
/*
$Var['SC']['hide'] = 'y';
function Test($FileName, $FileLine, $Opt='', $Col='') {
for ($Counter = 0; $Counter < 3; $Counter++) {
echo 'in for ';
if ( isset($Col['SC']['hide']) ) {
echo 'in if';
}
}
}
Test(__FILE__,__LINE__,'',$Var);
*/
# Set a single dimensional array,
# though continue to perform isset on a two dimensional
# Doesn't crash
# --> _BUT_ the "if isset()" test comes out as TRUE
# --> even when it's actually FALSE!
/*
unset($Var);
$Var['SC'] = 'y';
function Test($FileName, $FileLine, $Opt='', $Col='') {
for ($Counter = 0; $Counter < 3; $Counter++) {
echo 'in for ';
if ( isset($Col['SC']['hide']) ) {
echo 'in if';
}
}
}
Test(__FILE__,__LINE__,'',$Var);
*/
# Set variable to a string...
# okay
/*
$Var = 'y';
function Test($FileName, $FileLine, $Opt='', $Col='') {
for ($Counter = 0; $Counter < 3; $Counter++
[PHP-DEV] Bug #11218 Updated: isset() inside for() loops can crash
ID: 11218
Updated by: zeev
Reported By: [EMAIL PROTECTED]
Old-Status: Open
Status: Feedback
Bug Type: Scripting Engine problem
Operating system:
PHP Version: 4.0.5
Assigned To:
Comments:
I was unable to reproduce that problem, however, I did fix bug #10911 which appears to
be based on the same issue. Can you please test the latest CVS and see whether it
solves your problem (note, this fix may not be a part of 4.0.6, since 4.0.6 has
already been packaged; It'll definitely be in 4.0.7)
Previous Comments:
---
[2001-06-05 17:20:08] [EMAIL PROTECTED]
Bug 10911, http://www.php.net/bugs.php?id=10911, was brought to my attention. Both my
report above and this other one may be based on the same bug.
---
[2001-05-31 12:33:40] [EMAIL PROTECTED]
in for ';
if ( isset($Col['SC']['hide']) ) {
echo 'in if';
}
}
}
Test(__FILE__,__LINE__);
# NOW, funny things happen if I change the number of times
# the for loop runs...
# $Counter < 1...
# Everything is fine.
# $Counter < 2...
# Dr Watson notifys of PHP crash, hit OK
# (SeeDr Watson report at end of this posting.)
# Text is displayed in browser.
# PHP no longer running.
# $Counter < 3...
# Nothing returned to browser.
# No Dr Watson reports.
# PHP won't stop executing, takes up 99% of processor time.
# Can't "End Process" in Task Manger.
# Doesn't stop after max execution time.
# Need to reboot to kill PHP process.
#
# Though, if I execute from command line...
# winds up in same infinite loop, but I can
# kill the PHP process from the task manager.
# So, if that's not strange enough, altering the
# test code in small ways eliminates the problem...
# remove if / isset segment...
# okay
/*
function Test($FileName, $FileLine, $Opt='', $Col='') {
for ($Counter = 0; $Counter < 3; $Counter++) {
echo 'in for ';
}
}
Test(__FILE__,__LINE__);
*/
# put the if / isset segment back
# BUT remove the for loop
# okay
/*
function Test($FileName, $FileLine, $Opt='', $Col='') {
if ( isset($Col['SC']['hide']) ) {
echo 'in if';
}
}
Test(__FILE__,__LINE__);
*/
# put the for loop back
# BUT do isset on a single dimensional array...
# okay
/*
function Test($FileName, $FileLine, $Opt='', $Col='') {
for ($Counter = 0; $Counter < 3; $Counter++) {
echo 'in for ';
if ( isset($Col['SC']) ) {
echo 'in if';
}
}
}
Test(__FILE__,__LINE__);
*/
# perform tasks outside a function.
# okay
/*
for ($Counter = 0; $Counter < 3; $Counter++) {
echo 'in for ';
if ( isset($Col['SC']['hide']) ) {
echo 'in if';
}
}
*/
# set the array before running function
# okay
/*
$Var['SC']['hide'] = 'y';
function Test($FileName, $FileLine, $Opt='', $Col='') {
for ($Counter = 0; $Counter < 3; $Counter++) {
echo 'in for ';
if ( isset($Col['SC']['hide']) ) {
echo 'in if';
}
}
}
Test(__FILE__,__LINE__,'',$Var);
*/
# Set a single dimensional array,
# though continue to perform isset on a two dimensional
# Doesn't crash
# --> _BUT_ the "if isset()" test comes out as TRUE
# --> even when it's actually FALSE!
/*
unset($Var);
$Var['SC'] = 'y';
function Test($FileName, $FileLine, $Opt='', $Col='') {
for ($Counter = 0; $Counter < 3; $Counter++) {
echo 'in for ';
if ( isset($Col['SC']['hide']) ) {
echo 'in if';
}
}
}
Test(__FILE__,__LINE__,'',$Var);
*/
# Set variable to a string...
# okay
/*
$Var = 'y';
function Test($FileName, $FileLine, $Opt='', $Col='') {
for ($Counter = 0; $Counter < 3; $Counter++) {
echo 'in for ';
if ( isset($Col['SC']['hide']) ) {
echo 'in if';
}
}
}
Test(__FILE__,__LINE__,'',$Var);
*/
/*
Application exception occurred:
App: (pid=212)
When: 5/31/2001 @ 11:59:23.314
Exception number: c005 (access violation)
*> System Information <*
Computer Name: BASE
User Name: SYSTEM
Number of Processors: 1
Processor Type: x86 Family 6 Model 3 Stepping 4
Windows Version: 4.0
Current Build: 1381
Service Pack: 6
Current Type: Uniprocessor Free
Registered Organization: Analysis and Solutions Company
Registered Owner: Daniel Convissor
*> Task List <*
0 Idle.exe
2 System.exe
20 SMSS.exe
24 CSRSS.exe
34 winlogon.exe
40 SERVICES.exe
43 LSASS.exe
66 SPOOLSS.exe
