The relation of MM table records are saved wrong for element translations in TYPO3 8.7.
I appended a patch. I think it was just a small logic error. Hopefully I'm not totally wrong. :)
How to reproduce?
1. Create a TCA with an inline column. Both of them needs to use multilanguage settings.
2. The inline column needs to use the MM table configuration
3. Create some test records and localize them.
4. Go to the parent TCA in the default language.
You will see, that the localized records are shown within the default language with the default record under it in the inline element list. If you switch to the translation of the parent TCA, then you will see, that the records are missing, or shown as "not translated".
#2 Updated by Sybille Peters about 1 year ago
Thank you for your report.
Even though it has been some time, would you consider checking if your patch idea is still up to date and upload it to our Gerrit review server?
Someone could do this for you, but I am thinking you might like the opportunity to contribute to TYPO3 yourself.
You can find a description of the TYPO3 contribution workflow here: https://docs.typo3.org/typo3cms/ContributionWorkflowGuide/
Hint: If you get stuck anywhere, ask on Slack in the #typo3-cms-coredev channel. You can register in the TYPO3 slack workspace here: https://forger.typo3.com/slack
Also, if your issue is no longer reproducable, please let us know in the slack channel, so that this issue can be closed.
Thank you in advance!