blender
/
blender
128
396
Fork 568
Code Issues 6.2k Pull Requests 751 Projects 19 Wiki Activity

Fix T96289: Crash when accessing mesh via `ob.data` in a driver 

Fix a crash when a driver variable targets an object and uses
`data.shape_keys.key["name"].value` in its expression.

The fix consists of adding an extra relation from the targeted object's
`GEOMETRY` component to the driver evaluation. This ensures that its
`data` pointer has been evaluated by the depsgraph and is safe to
follow.

This also resolves the concern raised on rB56407432a6aa.

Reviewed by: brecht

Differential Revision: https://developer.blender.org/D14956
This commit is contained in:
Sybren A. Stüvel 2022-05-16 16:41:50 +02:00
parent 00af3e9472
commit a2dacefb46
Notes: blender-bot 2023-02-14 02:30:11 +01:00 
Referenced by issue #96289, Regression: Crash when accessing animated 'object.data' property in a driver of a Mesh
1 changed files with 16 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
source/blender/depsgraph/intern/builder/deg_builder_relations.cc
View File

@ -1693,6 +1693,22 @@ void DepsgraphRelationBuilder::build_driver_variables(ID *id, FCurve *fcu)
continue;
}
add_relation(variable_exit_key, driver_key, "RNA Target -> Driver");
/* The RNA getter for `object.data` can write to the mesh datablock due
* to the call to `BKE_mesh_wrapper_ensure_subdivision()`. This relation
* ensures it is safe to call when the driver is evaluated.
*
* For the sake of making the code more generic/defensive, the relation
* is added for any geometry type.
*
* See T96289 for more info. */
if (object != nullptr && OB_TYPE_IS_GEOMETRY(object->type)) {
StringRef rna_path(dtar->rna_path);
if (rna_path == "data" || rna_path.startswith("data.")) {
ComponentKey ob_key(target_id, NodeType::GEOMETRY);
add_relation(ob_key, driver_key, "ID -> Driver");
}
}
}
else {
/* If rna_path is nullptr, and DTAR_FLAG_STRUCT_REF isn't set, this