php.net |  support |  documentation |  report a bug |  advanced search |  search howto |  statistics |  random bug |  login

go to bug id or search bugs for

Bug #10292 Corrupted VARCHAR values from SELECT when used in arrays or array functions
Submitted: 2001-04-11 14:35 UTC Modified: 2001-05-03 03:32 UTC
From: lawe at tdk dot dk Assigned:
Status: Closed Package: InterBase related
PHP Version: 4.0.4pl1 OS: Linux / Windows
Private report: No CVE-ID: None
View Developer Edit
Welcome back! If you're the original bug submitter, here's where you can edit the bug or add additional notes.
If you forgot your password, you can retrieve your password here.
Password:
Status:
Package:
Bug Type:
Summary:
From: lawe at tdk dot dk
New email:
PHP Version: OS:

 

 [2001-04-11 14:35 UTC] lawe at tdk dot dk 
// f1 and f2 are of type varchar
$id=ibase_query($tr_id, "SELECT f1, f2 FROM t1;");
$res = ibase_fetch_row($id);
echo "'".$res[0]."'";  // Working fine
$arr[$res[0]] = 1;
$arr[$res[1]] = 2;
foreach ($res as $r => $v)
  echo "'$r'\n";     // will in some cases add unexpected
                     // characters to end of $r
                     // It is the same with each construct
// The same applies to ibase_fetch_object()

The values in the database are correct, as the unwanted characters may vary depending on the number of columns in the select-statement. But it is always the same characters on repeated executions.
I have made a work-around in a way like this:
$arr[str_pad($res[0], -1)] = 1;

I think it has something to do with the Interbase-API, as it is the same errors regardless of the Webserver (Apache 1.3.14 & 1.3.19, PHP 4.0.4pl1 or Win9x PWS, CGI or ISAPI version of PHP 4.0.4pl1) connecting to Interbase 6.01 on RedHat 6.1 and RedHat 6.2

The bug was first observed when doing a split(), where the last element in the resulting array had strange characters attached to the end.

PHP configured with minimal changes to defaults (Interbase support, enable-track-vars).

Hope this is sufficient information, otherwise write me for further info, and I will try to deliver it (if I can).

Regards
/Lars

Patches

Pull Requests

History

AllCommentsChangesGit/SVN commitsRelated reports
 [2001-04-23 04:31 UTC] lawe at tdk dot dk 
Hi!

I finally found the bug myself. And it was indeed in ./ext/interbase.c

Normally you would terminate a string explicitly after a strncpy(), but one should think this was unnecessary in this part of the code, as the string-length is part of the variable-structure. Nevertheless I added a statement which filled in the missing zero to end the string, and Voila! All the strange characters disappeared. Could it be, that the code handling the PHP-arrays doesn't use the len-parameter, but only uses the estrdup() function (which assumes a correctly terminated string)?

In the same function I also discovered a memoryleak when handling magic-quotes, so the final diff between the new interbase.c and the old one (version 1.48) looks like this (I have removed many of the leading spaces):

$ diff interbase.c interbase.orig.c
1009c1009
< IB_ARRAY[ar_cnt].el_type = SQL_VARYING;
---
> IB_ARRAY[ar_cnt].el_type = SQL_TEXT;
1731d1730
<           val->value.str.val[len] = 0;
1733c1732,1738
< val->value.str.val = php_addslashes(val->value.str.val, len, &len, 1);  /* Old string should be deleted */
---
> /*
> char *tmp = val->value.str.val;
> */
> val->value.str.val = php_addslashes(val->value.str.val, len, &len, 0);
> /*
> efree(tmp);
> */
$

The first change is questioned in the code, so I just changed it! - and from my testing there wasn't any changed (or erroneous) behaviour noticed.
The two other changes are the string-termination bugfix and the memory-leak bugfix.

I have seen another bugreport concerning the formatting of the floating-point datatypes - I am currentliy not using floating-point fields in my databases, but maybe one should take a look at the FP-handling in the same function (_php_ibase_var_pval())?

Yours sincerely,
Lars

PS! Keep up the good work - PHP is great!
 [2001-05-03 03:32 UTC] sniper@php.net 
Should be fixed in CVS now.

--Jani
 
PHP Copyright © 2001-2024 The PHP Group
All rights reserved. 		Last updated: Sat Dec 21 17:01:58 2024 UTC