Change the way how lifetimes work in ext/dom #11576
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Previously, a node could be freed even when holding a userland reference to it. This resulted in exceptions when trying to access that node after it has been implicitly or explicitly removed. After this patch, a node will only be freed when the last userland reference disappears.
Girgias
reviewed
Jul 3, 2023
ext/dom/document.c
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| @@ -2141,7 +2138,7 @@ PHP_METHOD(DOMDocument, registerNodeClass) | |||
| } | |||
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| if (ce == NULL || instanceof_function(ce, basece)) { | |||
| DOM_GET_OBJ(docp, id, xmlDocPtr, intern); | |||
| DOM_GET_INTERN(id, intern); | |||
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Is it me, or is id always just ZEND_THIS ?
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Most of the time yes. I'll fold that in.
Girgias
approved these changes
Jul 3, 2023
With the new lifetime system in place, we can simplify some macros.
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Fixes GH-9628
Currently, when you remove a node from the DOM, that node will become inaccessible. This even happens when the node is implicitly removed, even when you still hold a reference to it in a variable. This is not possible to detect and prevent easily (see issue details).
This patch changes how lifetimes works. If there's still a userland reference, the node is unlinked instead of freed.
This causes some complications because of how freeing works, especially because of some libxml2 peculiarities (see comments in the code).