JsFooterPlugin sets Http Response content empty if PCRE limit reached

[cundd]

Preconditions (*)

1. Magento 2.3.2-p2
2. PHP 7.1
3. pcre.backtrack_limit = 1000000 (Default)
4. pcre.recursion_limit = 1000000 (Default)
5. dev/js/move_script_to_bottom=enabled

Steps to reproduce (*)

1. Build a huge HTML output (e.g. shopping cart with a lot of complex products)

Expected result (*)

1. Output should be turned or error should be thrown

Actual result (*)

1. A HTTP status code 200 without a response body is returned

The call to preg_replace_callback() in JsFooterPlugin will fail silently, resulting in a blank page. The reason for this is, that preg_replace_callback() will return NULL if one of it's limits is reached. NULL will further be used to set the content of the HTTP response.

A first step would be to check if the result of preg_replace_callback() is NULL and throw an appropriate exception (generated from preg_last_error()).

[m2-assistant]

Hi @cundd. Thank you for your report.
To help us process this issue please make sure that you provided the following information:

• Summary of the issue
• Information on your environment
• Steps to reproduce
• Expected and actual results

Please make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce. To deploy vanilla Magento instance on our environment, please, add a comment to the issue:

@magento give me 2.4-develop instance - upcoming 2.4.x release

For more details, please, review the Magento Contributor Assistant documentation.

@cundd do you confirm that you were able to reproduce the issue on vanilla Magento instance following steps to reproduce?

• yes
• no

---

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[cundd]

@magento give me 2.4-develop instance

[magento-engcom-team]

Hi @cundd. Thank you for your request. I'm working on Magento 2.4-develop instance for you

[magento-engcom-team]

Hi @cundd, here is your Magento instance.
Admin access: https://i-26026-2-4-develop.instances.magento-community.engineering/admin
Login: admin Password: 123123q
Instance will be terminated in up to 3 hours.

[cundd]

I couldn't manage to reproduce it with the admin access only, but fixing this would more be a general improvement to the Magento framework, rather than an immediate fix for a bug.

[m2-assistant]

Hi @engcom-Echo. Thank you for working on this issue.
In order to make sure that issue has enough information and ready for development, please read and check the following instruction: 👇

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[magento-engcom-team]

✅ Confirmed by @engcom-Echo
Thank you for verifying the issue. Based on the provided information internal tickets MC-29768 were created

Issue Available: @engcom-Echo, You will be automatically unassigned. Contributors/Maintainers can claim this issue to continue. To reclaim and continue work, reassign the ticket to yourself.

[magento-engcom-team]

Hi @cundd. Thank you for your report.
The issue has been fixed in #27270 by @krzksz in 2.4-develop branch
Related commit(s):

• 31eeaa7b5b18d27fc786660d23faaba6ff0393d1
• 4fa54472bab13709e6f320fea97bdc94f330bcfd
• 08f2bd4b92603363d8cd5f2ca4ffbbbdd454b6e9
• 2c5bc50da87ac7a6471dc36759f37bf817a39e06
• 27805df2d2d61bb2290123ad6bdf8e1b0939e42a
• 693507fde3894bbe98b77b4b24740b9503244f9f
• 31b045682218f127a6239de1ff8bafd9b4dde4df
• b54ce80fa8845358d9f8c7ddc76a4f076e885e62
• 036f99fd1e6996724d9d91af19e9ff2edb0bb9ca
• 9687370475af12abea586dd94bfb1ede3800acb2
• e38b1a116daf637bb212e8c60603e940bac7a642
• 1b780be6c1d75cce024446e33446ef4b29d3f827
• b7ff624737a78f3a09a8b92ea7a691c621fb1153
• ffd392cbf9d61815846f40dec9d5591f579883da
• d963abc3173d7425d71d03076f4a681fccf9fbad
• 44131f8bc2fed8534995da0e43bfd2310fe78ff8

The fix will be available with the upcoming 2.4.0 release.