Correct Cache setWorkarounds to take account of multiple script or st…

[GeraintEdwards]

…yle declarations being used that mean that we have an array of scripts or stylesheets to be cached and not just a string

Cache setWorkarounds returns an array not a string

Pull Request for Issue # .

Summary of Changes

Correct Joomla\CMS\Cache Cache setWorkarounds to take account of multiple script or style declarations being used that mean that we have an array of scripts or stylesheets to be cached and not just a string
Joomla\CMS\Cache Cache setWorkarounds returns an array not a string

Testing Instructions

1. On a Joomla 4-dev site install this module https://www.yoursites.net/testextensions/mod_cachetest.zip
2. Create 2 instances of this module to display on the same page in different module positions - leave caching setting as 'global' in module settings
3. Enable Joomla conservative caching in Joomla config
4. Enable maximum error reporting in Joomla config#
5. Make sure the Joomla cache is cleared
6. Load the frontend page where modules are displayed
7. Reload the frontend page

Actual result BEFORE applying this Pull Request

At Step 6 you get a php warning on arguments to mb_strlen and 4 javascript alert messages

See https://www.yoursites.net/testextensions/Screenshot%202021-11-17%20at%2010-05-05%20Home.png

At step 7 you get a different PHP warning from libraries/src/Document/HtmlDocument.php because it expects an array but has been given a script by Cache.php

Expected result AFTER applying this Pull Request

Page is displayed with no warning messages and module content is delivered from the cache correctly with 4 alerts

Documentation Changes Required

[tonypartridge]

@brianteeman would you have a minute some time to test?

I'll do one tomorrow.

[brianteeman]

At Step 6 you get a php warning on arguments to mb_strlen and 4 javascript alert messages

I do not get the same results as you at this step. I just get an error page with this error
mb_strlen(): Argument #1 ($string) must be of type string, array given

Which means that step 7 can never occur

[GeraintEdwards]

@brianteeman Its the same problem the cache code is applying strlen to an array.

I had error reporting enabled but not joomla debug mode when I was testing

[brianteeman]

I enabled debug because you had it enabled in your screenshot ;)

With or without the debug I get the error page and not what you described

[GeraintEdwards]

If you look at the screenshot of your debug trace notice that line 4 in the stack refers to line 694 of the file Cache.php - this is exactly where I am saying the error arises. If you are still seeing a reference to strlen error on line 694 of Cache.php then you I suspect you are seeing a cached version of the error output since line 694 no longer has a call to StringHelper::strlen in my version of the code.

If you apply the fix and clear the cache and repeat the test the error you are seeing should not appear.

[tonypartridge]

I have tested this item ✅ successfully on 21715f3

Tested Successfully, pre-patch clearly shows the error

Warning
: mb_substr() expects parameter 1 to be string, array given in
/var/www/joomla4/libraries/vendor/joomla/string/src/phputf8/mbstring/core.php
on line

On applying patch without clearing cache we get:

Warning
: Invalid argument supplied for foreach() in
/var/www/joomla4/libraries/src/Document/HtmlDocument.php
on line
389

Clearing cache with path applied it loads without error.

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[GeraintEdwards]

Thanks @tonypartridge - forgot to emphasise that after applying the fix it is ESSENTIAL to clear the cache.

The error in HtmlDocument.php that you saw is a secondary manifestation of the same problem - Cache.php is storing the the cached data as a string but HtmlDocument.php is expecting it to be an array. My change resolves this issue (as you discovered)

[GeraintEdwards]

@Fedik Would you mind taking a look at this issue and PR please - your PR ( in https://github.com/joomla/joomla-cms/commit/86a0d88e415112553ede15e989cfa1b81a32e15c) stored the scripts and styles as arrays but these changes should have been carried over to the Cache system too. This PR resolves these issues.

Thanks

[Fedik]

From code review it looks good,
I try to test a bit later

[Fedik]

I have tested this item ✅ successfully on 21715f3

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[Fedik]

r
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[pritam825]

I have tested this item ✅ successfully on 21715f3

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[khu5h1]

I have tested this item ✅ successfully on 21715f3

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[wilsonge]

Thanks!