Philipp Parzer authored Nov 06, 2020 and Christian Kuhn committed Mar 25, 2021

Scenario:
A content element 'ce-1-default' exists on a 'source' page. It
has a 'free mode' localization 'ce-1-localized'. The localized
content element thus has l18n_parent=0 (free mode) and
l10n_source='id-of-ce-1-default' - it has been derived from
'ce-1-default'.

Now 'ce-1-default' is moved to a different 'target' page. Due to
free mode, 'ce-1-localized' is NOT moved along with it's localization
source, but keeps l10n_source='id-of-ce-1-default' (this needs to be
discussed if we change this) and stays on 'source' page. This is ok.

Now, a new content element 'ce-2-default' is added on 'target' page,
right below the previously moved 'ce-1-default'. And then, this
element is localized.

DataHandler now tries to find out where to create this localized
'ce-2-localized' record relative to other records. It finds the
localization 'ce-1-localized' due to its l10n_source indicator
and then creates 'ce-2-localized' after 'ce-1-localized'. On the
source page!
So the content element localization ends up on a different page,
which is of course wrong, misleading and hard to understand!

To fix this, the Datahandler now finds translated content elements
of a given content element only if it is on the same page. This
keeps this 'relative-to' magic, and the content element does not
end up on some foreign page.

Resolves: #92783
Resolves: #92198
Releases: master, 10.4
Change-Id: I104a4b2d59322ec55ad96e37e8d1b3c3fed0e515
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/66552


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>