ignore_repeated_errors ini entry does not work

[michaelbrauchl-a11y]

Description

The following code:

<?php
ini_set('ignore_repeated_errors', 1);
for($i=0; $i<10; $i++ ) {
	trim($at);
}
?>

Resulted in this output in the error-log-file:

[18-Aug-2025 04:51:50 Europe/Vienna] PHP Warning:  Undefined variable $at in D:\Projekte\System\error_test\test.php on line 4
[18-Aug-2025 04:51:50 Europe/Vienna] PHP Warning:  Undefined variable $at in D:\Projekte\System\error_test\test.php on line 4
[18-Aug-2025 04:51:50 Europe/Vienna] PHP Warning:  Undefined variable $at in D:\Projekte\System\error_test\test.php on line 4
[18-Aug-2025 04:51:50 Europe/Vienna] PHP Warning:  Undefined variable $at in D:\Projekte\System\error_test\test.php on line 4
[18-Aug-2025 04:51:50 Europe/Vienna] PHP Warning:  Undefined variable $at in D:\Projekte\System\error_test\test.php on line 4
[18-Aug-2025 04:51:50 Europe/Vienna] PHP Warning:  Undefined variable $at in D:\Projekte\System\error_test\test.php on line 4
[18-Aug-2025 04:51:50 Europe/Vienna] PHP Warning:  Undefined variable $at in D:\Projekte\System\error_test\test.php on line 4
[18-Aug-2025 04:51:50 Europe/Vienna] PHP Warning:  Undefined variable $at in D:\Projekte\System\error_test\test.php on line 4
[18-Aug-2025 04:51:50 Europe/Vienna] PHP Warning:  Undefined variable $at in D:\Projekte\System\error_test\test.php on line 4
[18-Aug-2025 04:51:50 Europe/Vienna] PHP Warning:  Undefined variable $at in D:\Projekte\System\error_test\test.php on line 4

But I expected this output in the error-log-file instead:

[18-Aug-2025 04:51:50 Europe/Vienna] PHP Warning:  Undefined variable $at in D:\Projekte\System\error_test\test.php on line 4

PHP Version

PHP 8.4.11 cli

Operating System

Windows Server 2019

[hakre]

This is probably since PHP 8.1 as it emits a deprecation immediately afterwards, making it non-repeatable?

Compare:

$ php8.1 -n -d display_errors=2 -r '
ini_set("ignore_repeated_errors", 1);
for($i=0; $i<3; $i++ ) {
        trim($at);
}'
Warning: Undefined variable $at in Command line code on line 4
Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated in Command line code on line 4
Warning: Undefined variable $at in Command line code on line 4
Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated in Command line code on line 4
Warning: Undefined variable $at in Command line code on line 4
Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated in Command line code on line 4

Given the reporting is limited at warnings (including), it shows the reported picture:

$ php8.1 -n -d display_errors=2 -d error_reporting=3 -r '
ini_set("ignore_repeated_errors", 1);
for($i=0; $i<3; $i++ ) {
        trim($at);
}'
Warning: Undefined variable $at in Command line code on line 4
Warning: Undefined variable $at in Command line code on line 4
Warning: Undefined variable $at in Command line code on line 4

Which makes sense in terms of ignoring errors, but does it make sense in terms of reporting errors? @michaelbrauchl-a11y

[michaelbrauchl-a11y]

Maybe a misunderstanding depending on the language, i'm german native speaker. From my understanding, the directive "ignore_repeated_errors" should report the first error+warning+notice (dependinmg on the setting of error_reporting) and omit afterwards following same errors/warnings/notices. I may be wrong, but i think in php 7.2 it works this way. I would expect this entries in the error_log: Warning: Undefined variable $at in Command line code on line 4 Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated in Command line code on line 4 And thats all. Regards Michael Von: "hakre" ***@***.***> An: "php/php-src" ***@***.***> Kopie: "michaelbrauchl-a11y" ***@***.***>, "Mention" ***@***.***> Datum: 18.08.2025 08:42 Betreff: [EXTERNAL] Re: [php/php-src] ignore_repeated_errors ini entry does not work (Issue #19509)

…

--- This message is from an EXTERNAL SENDER - be CAUTIOUS, particularly with links and attachments! --- hakre left a comment (php/php-src#19509) This is probably since PHP 8.1 as it emits a deprecation immediately afterwards, making it non-repeatable? Compare: $ php8.1 -n -d display_errors=2 -r ' ini_set("ignore_repeated_errors", 1); for($i=0; $i<3; $i++ ) { trim($at); }' Warning: Undefined variable $at in Command line code on line 4 Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated in Command line code on line 4 Warning: Undefined variable $at in Command line code on line 4 Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated in Command line code on line 4 Warning: Undefined variable $at in Command line code on line 4 Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated in Command line code on line 4 Given the reporting is limited to warnings, it shows the reported picture: $ php8.1 -n -d display_errors=2 -d error_reporting=3 -r ' ini_set("ignore_repeated_errors", 1); for($i=0; $i<3; $i++ ) { trim($at); }' Warning: Undefined variable $at in Command line code on line 4 Warning: Undefined variable $at in Command line code on line 4 Warning: Undefined variable $at in Command line code on line 4 Which makes sense in terms of ignoring errors, but does it make sense in terms of reporting errors? @michaelbrauchl-a11y ? Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you were mentioned.Message ID: ***@***.***>

[iluuu1994]

Hi @michaelbrauchl-a11y

From my understanding, the directive "ignore_repeated_errors" should report the first error+warning+notice (dependinmg on the setting of error_reporting) and omit afterwards following same errors/warnings/notices.

That interpretation is very logical given the name, but also inaccurate. Such an implementation would require recording all errors that occur over the lifetime of the application. That wouldn't be a huge deal, but it's not how this was implemented. Instead, what it does is record the last error that occurred, and omit the error if it happens to be equal to the last one. The documentation is pretty vague on this and could be improved.

https://www.php.net/manual/en/errorfunc.configuration.php#ini.ignore-repeated-errors

I may be wrong, but i think in php 7.2 it works this way.

This feature was actually completely broken before PHP 8.0. It did the exact opposite of what it was supposed to do, it suppressed error only if it was different from the last one. 4c171ed

[hakre]

Maybe a misunderstanding depending on the language, i'm german native
speaker.

I'm with you, and yes, this is something I also learned the hard way - just some years earlier probably.

The documentation is pretty vague on this and could be improved.

I'll consider that, seems appropriate to me as I wondered as well. When I create a PR in the documentation repository, then I will reference this issue here.

I may be wrong, but i think in php 7.2 it works this way.

This feature was actually completely broken before PHP 8.0. It did the exact opposite of what it was supposed to do, it suppressed error only if it was different from the last one. 4c171ed

But @michaelbrauchl-a11y is correct, too. It did work in 7.2 and 7.4 because the deprecation notice was not there.

$ php7.2 -n -d display_errors=2 -d error_reporting=-1 -r '
ini_set("ignore_repeated_errors", 1);
for($i=0; $i<3; $i++ ) {
        trim($at);
}'
Notice: Undefined variable: at in Command line code on line 4

[alecpl]

As far as I checked it worked in PHP7. It got broken in PHP 8.0, then fixed in 8.0.14 and again broken in 8.1.

[iluuu1994]

As far as I checked it worked in PHP7. It got broken in PHP 8.0, then fixed in 8.0.14

I see, it was only broken for 8.0.0 - 8.0.13.

and again broken in 8.1.

It's only "broken" in 8.1 because that's when the Passing null to parameter of type string is deprecated deprecation was introduced. The feature itself works the same as before.

[alecpl]

It's only "broken" in 8.1 because that's when the Passing null to parameter of type string is deprecated deprecation was introduced. The feature itself works the same as before.

No, not really. Try this

<?php

ini_set("ignore_repeated_errors", 1);
ini_set('error_reporting', 3);
for($i=0; $i<3; $i++ ) {
        trim($at);
}

[iluuu1994]

See https://3v4l.org/RaQKs. This isn't more broken than in 7.4. The last error is stored/replaced even if the error is suppressed, but this hasn't changed. It would make sense to adjust it, I agree, but this is long-standing behavior.

[iluuu1994]

This seems to be based on PG(last_error_message), which is also exposed via error_get_last(). We would need to store the last message in a new global. I also learned that ignore_repeated_errors has no effect on user error handlers, i.e. error handlers are called even if the message is repeated, which makes this feature pretty much useless.

Maybe the feature can be adapted to become more useful, but in that case I think this needs a discussion on the internals mailing list. Please proceed if this is something you'd like to see, with a concrete suggestion on what should be changed.