TYPO3 Core

What appears to be happening:

• ContentObjectRenderer is instantiated without constructor TypoScriptFrontendController argument
• getTypoScriptFrontendController on same class then returns $_GLOBALS['TSFE']
• State of $GLOBALS['TSFE'] appears to become mutated
• State is not reset when ending content rendering

I believe the problem is the recursiveness: when TypoScriptFrontendController renders any content element it mutates it's own state with various stack depth counters etc., thus rendering another content element inside that content element causes issues with that mutated TSFE state. Code that executes after a second "content object" (it isn't actually an editor-inserted content object but gets rendered as if it were!) is rendered then either has a cleaned state or incorrectly sees properties of the secondary "content object" that was rendered. I didn't check which it is.

Possible solutions:

1. Pass a clone of TSFE as constructor argument for `ContentObjectRenderer`
2. Use a freshly created TypoScriptFrontendController (avoid ContentObjectRenderer, do not reuse TSFE global)

I would suggest either one as valid. Another benefit would become able to pass a simulated TSFE instance to this method. See #73183 for some further perspectives about the benefits of that ability.

Set to follow #73183 since merging that one would provide a neat API to get a simulated ContentObjectRenderer ideal for use in ``f:cObject``.

Patch set 2 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/58661

Patch set 3 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/58661

Patch set 4 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/58661

Patch set 5 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/58661

Patch set 6 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/58661

Patch set 7 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/58661

Patch set 8 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/58661

I tried to reproduce the issue as reported on the issue https://forge.typo3.org/issues/87003 which has been marked as a duplicate, following these steps on TYPO3 9.5.5

1) In a Fluid Page Template, I put:

<f:debug>{data}</f:debug>

and it outputs the data of the page (title, slug,etc)

2) On a page, I put a plugin "Form" element

Results:¶

The data shown are still that from the page