Depsgraph crash when calling to_mesh() on a Curve object after clearing its parent #38337

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Tom Edwards · 2014-01-23T15:55:37+01:00

Tom Edwards commented

2014-01-23 15:55:37 +01:00

System Information
Win7 x64, GTX560

Blender Version
Broken: c37e8ecc
Worked: 2.69

When clearing an object's parent, the scene's entire DAG is freed. Converting a Curve object to a mesh (via ob.to_mesh()) leads to an attempt to access the DAG without first checking whether it exists, which crashes Blender.

Callstack:

blender.exe!dag_find_node(DagForest * forest, void * fob) Line 992	C
blender.exe!DAG_get_eval_flags_for_object(Scene * scene, void * object) Line 2945	C
blender.exe!do_makeDispListCurveTypes(Scene * scene, Object * ob, ListBase * dispbase, DerivedMesh * * derivedFinal, int forRender, int forOrco, int renderResolution) Line 1571	C
blender.exe!BKE_displist_make_curveTypes_forRender(Scene * scene, Object * ob, ListBase * dispbase, DerivedMesh * * derivedFinal, int forOrco, int renderResolution) Line 1619	C
blender.exe!rna_Main_meshes_new_from_object(Main * bmain, ReportList * reports, Scene * sce, Object * ob, int apply_modifiers, int settings, int calc_tessface, int calc_undeformed) Line 318	C
blender.exe!rna_Object_to_mesh(Object * ob, ReportList * reports, Scene * sce, int apply_modifiers, int settings, int calc_tessface, int calc_undeformed) Line 121	C
blender.exe!Object_to_mesh_call(bContext * C, ReportList * reports, PointerRNA * _ptr, ParameterList * _parms) Line 4780	C

Exact steps for others to reproduce the error

Open curve_bake_crash.blend and run the script in the text editor.

**System Information** Win7 x64, GTX560 **Blender Version** Broken: c37e8ecc Worked: 2.69 When clearing an object's parent, the scene's entire DAG is freed. Converting a Curve object to a mesh (via `ob.to_mesh()`) leads to an attempt to access the DAG without first checking whether it exists, which crashes Blender. Callstack: ``` blender.exe!dag_find_node(DagForest * forest, void * fob) Line 992 C blender.exe!DAG_get_eval_flags_for_object(Scene * scene, void * object) Line 2945 C blender.exe!do_makeDispListCurveTypes(Scene * scene, Object * ob, ListBase * dispbase, DerivedMesh * * derivedFinal, int forRender, int forOrco, int renderResolution) Line 1571 C blender.exe!BKE_displist_make_curveTypes_forRender(Scene * scene, Object * ob, ListBase * dispbase, DerivedMesh * * derivedFinal, int forOrco, int renderResolution) Line 1619 C blender.exe!rna_Main_meshes_new_from_object(Main * bmain, ReportList * reports, Scene * sce, Object * ob, int apply_modifiers, int settings, int calc_tessface, int calc_undeformed) Line 318 C blender.exe!rna_Object_to_mesh(Object * ob, ReportList * reports, Scene * sce, int apply_modifiers, int settings, int calc_tessface, int calc_undeformed) Line 121 C blender.exe!Object_to_mesh_call(bContext * C, ReportList * reports, PointerRNA * _ptr, ParameterList * _parms) Line 4780 C ``` **Exact steps for others to reproduce the error** - Open [curve_bake_crash.blend](https://archive.blender.org/developer/F74047/curve_bake_crash.blend) and run the script in the text editor.

Tom Edwards commented

2014-01-23 15:55:37 +01:00

Changed status to: 'Open'