Bug #78932 [Ver]: Cannot fetch mysqli_prepare error if $statement variable reused
| From: | nikic@php.net | Date: | Mon, 09 Dec 2019 08:36:55 +0000 |
| Subject: | Bug #78932 [Ver]: Cannot fetch mysqli_prepare error if $statement variable reused | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-224154@lists.php.net to get a copy of this message | ||
Edit report at https://bugs.php.net/bug.php?id=78932&edit=1
ID: 78932
Updated by: nikic@php.net
Reported by: craig at craigfrancis dot co dot uk
Summary: Cannot fetch mysqli_prepare error if $statement
variable reused
Status: Verified
Type: Bug
Package: MySQLi related
PHP Version: 7.3.12
Block user comment: N
Private report: N
New Comment:
The problem here is that the original $statement gets destroyed when the next assignment to the
variable happens (that is, after the second prepare has finished). When the old $statement is
destroyed a close_on_server operation on the statement is issued. This is going to reset the error
state, because it performs a number of operations that may in themselves fail (like exhausting the
result and closing the statement), and the error result from those operations will be used. As they
don't fail, the error ends up being zero.
I don't really know what we should be doing about this. I guess one possibility is to back up
the error information before we do an *implicit* close, as opposed to an explicit close with
mysqli_stmt_close() (in which case we *do* want to report errors from that operation).
Previous Comments:
------------------------------------------------------------------------
[2019-12-09 08:26:16] nikic@php.net
Also reproduces on older PHP versions.
------------------------------------------------------------------------
[2019-12-08 21:27:49] craig at craigfrancis dot co dot uk
Description:
------------
When running the following test script, the error is not correctly shown.
But if you un-commented the
$statement = false line, then it works.
It's as though the $statement variable is not being properly replaced.
Test script:
---------------
<?php
$link = mysqli_connect('localhost', 'username', 'password',
'database');
$statement = mysqli_prepare($link, 'SELECT 1');
// $statement = false;
$statement = mysqli_prepare($link, 'SELECT 1 FROM this_table_does_not_exist');
if (!$statement) {
exit(mysqli_errno($link) . ': ' . mysqli_error($link));
}
?>
Expected result:
----------------
1146: Table 'database.this_table_does_not_exist' doesn't exist
Actual result:
--------------
0:
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=78932&edit=1