TYPO3 Core

There is 2 reasons of this (kind of) bug :

First is that tslib_fe->getPageAndRootline method "clean" the MP var if ANY shortcut is found in the rootline (which is definitively wrong, according to the comment :

// We need to clear MP if the page is a shortcut. Reason is IF the short cut goes to another page, then we LEAVE the rootline which the MP expects.
So, as explained by the comment, IF the short cut DOES NOT go to another page, we have a weird behaviour. That's why (based on my comprehension of the mechanics) it should be tslib_fe->getPageShortcut responsability to clear OR NOT the MP var (only if needed).

Second reason is that tslib_fe->getPageShortcut fails himself while resolving shortcut with a "shortcut mode". The function t3lib_pageselect->getMenu is used to get shortcut subpages. This function store MP information in a "virtual" field "_MP_PARAM" in the results, and this information IS NOT USED !

My first patch resolves this 2 problems (the second patch is EXACTLY the same but I HAD TO REMOVE the "while list = each"), assuming the MPvar order is not wrong (in my code) or not important (for the core)

The issue is still present in 4.4.

Popy patch is quite OK for the 2 special shortcut modes (first page & random), he let the actual shortcut to clear the MP context.
It would be better to improve the shortcut mode with a test : should the source and the target of the shortcut be in the same rootline, the MP params need to be preserved (IMHO).

The problem is hidden in menus in TYPO3 >= 4.6, because of #32938, but still exists under the hood (= if you call a shortcut directly).

Patch set 1 for branch master has been pushed to the review server.
It is available at http://review.typo3.org/10100

Patch set 1 for branch TYPO3_4-7 has been pushed to the review server.
It is available at http://review.typo3.org/10101

Patch set 1 for branch TYPO3_4-6 has been pushed to the review server.
It is available at http://review.typo3.org/10102

Patch 17537-v3.diff solves the problems in TYPO3 4.5.25 but in our case only shortcuts of mode "first subpage of current page". If shortcut-mode is "selected page" the mp-parameters will be lost... But we need this behavior even in shortcuts of mode "selected page" and the following lines fix the problem in our case:

function getPageShortcut($SC,$mode,$thisUid,$itera=20,$pageLog=array()) {
...
switch($mode) {
...
default:
//$this->MP = '';
...
break;
...
}

Patch set 2 for branch master has been pushed to the review server.
It is available at https://review.typo3.org/10100

Patch set 3 for branch master has been pushed to the review server.
It is available at https://review.typo3.org/10100

Patch set 4 for branch master has been pushed to the review server.
It is available at https://review.typo3.org/10100

Patch set 5 for branch master has been pushed to the review server.
It is available at https://review.typo3.org/10100

Stephan Vidar wrote:

Patch 17537-v3.diff solves the problems in TYPO3 4.5.25 but in our case only shortcuts of mode "first subpage of current page". If shortcut-mode is "selected page" the mp-parameters will be lost... But we need this behavior even in shortcuts of mode "selected page" and the following lines fix the problem in our case:

function getPageShortcut($SC,$mode,$thisUid,$itera=20,$pageLog=array()) {
...
switch($mode) {
...
default:
//$this->MP = '';
...
break;
...
}

The problem is that shortcuts to pages outside the mountpoint will fail again with your solution. We have to differentiate between two different cases: The shortcut target is either (a) within or (b) not within the mounted subtree where the shortcut resides.

Ideally, this should be respected when generating the menu links, though it will still work if it is only done when resolving the shortcut.

Patch set 6 for branch master has been pushed to the review server.
It is available at https://review.typo3.org/10100

Patch set 7 for branch master has been pushed to the review server.
It is available at https://review.typo3.org/10100

Patch set 8 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at http://review.typo3.org/10100

Patch set 9 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at http://review.typo3.org/10100

Patch set 10 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/10100

Patch set 11 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/10100

In TYPO3 9.5.1-dev, the issue is solved:

Links to external urls in mounted subtrees don't keep the MP-Parameter.
In shortcuts the MP-Parameter ist kept.

in TYPO3 8.7.20-dev the issue is solved, too.

Same behaviour like in 9.5