TYPO3 Core

Hi,
after a bit of investigation I think there is something wrong in
TYPO3\CMS\Backend\Security\CategoryPermissionsAspect around lines 70-86

               foreach ($startingPoints as $startingPoint) {

                        if (!in_array($startingPoint, $categoryMountPoints)) {
                            $shallRepopulateTree = true;
                            break;
                        }
                        $uidsInRootline = $this->findUidsInRootline($startingPoint);
                        if (empty(array_intersect($categoryMountPoints, $uidsInRootline))) {
                            $shallRepopulateTree = true;
                            break;
                        }
                }

With the for loop we check whether startingpoints are present in the user's categorymounts,
but the starting points can be (as in my case) subcategories of a category mount points so the if statement is false, the variable $shallRepopulateTree is set to true and the cycle is interrupted, causing the reconstruction of the tree without the categories corresponding to the starting point

It's definitely this part, because if I comment it out, the tree is built up correctly.

So I dug deeper:
If the starting point (or back then the rootUid) is a category mount point before the changes for https://forge.typo3.org/issues/95037 the tree wasn't touched.

                    if (in_array($dataProvider->getRootUid(), $categoryMountPoints)) {
                        return;
                    }

Now its rootline is also checked and that's where it all goes wrong...

I'm sure this needs more testing but in my case this worked:

                foreach ($startingPoints as $startingPoint) {
                    if (in_array($startingPoint, $categoryMountPoints)) {
                        $shallRepopulateTree = false;
                        break;
                    }
                    $uidsInRootline = $this->findUidsInRootline($startingPoint);
                    if (!empty(array_intersect($categoryMountPoints, $uidsInRootline))) {
                        $shallRepopulateTree = false;
                        break;
                    }
                    $shallRepopulateTree = true;
                }

Maybe this $shallRepopulateTree = false; isn't needed as false is the inital value.

EDIT:
This only works if a starting point is set... So I changed it to:

                foreach ($startingPoints as $startingPoint) {
                    if ($startingPoint) {
                        if (in_array($startingPoint, $categoryMountPoints)) {
                            $shallRepopulateTree = false;
                            break;
                        }
                        $uidsInRootline = $this->findUidsInRootline($startingPoint);
                        if (!empty(array_intersect($categoryMountPoints, $uidsInRootline))) {
                            $shallRepopulateTree = false;
                            break;
                        }
                        $shallRepopulateTree = true;
                    }
                }