Change Details

**System Information** Operating system: Linux-4.15.0-117-generic-x86_64-with-debian-buster-sid 64 Bits Graphics card: GeForce GTX 1050/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 435.21 **Blender Version** Broken: version: 2.90.1, branch: master, commit date: 2020-09-23 06:43, hash: `rB3e85bb34d0d7` Worked: 2.82 **Short description of error** This is a follow-up to https://developer.blender.org/T80217 I'm using the update callback of an enum prop to append an object from an external blend file, then link it to the master collection. This is a fairly standard procedure for addons using template icon views to "load assets". In the previous report, it was suggested to not call an operator from the update callback to prevent crashes, if the user were to undo after such an "asset load". This new report then avoids using an operator and instead uses a dedicated `append_object_function()`. Unfortunately the crash is still happening as soon as one does an undo. As in the previous report, appending using `layout.operator()` works fine. All of this worked up until 2.82 and 2.83 was the first to crash. If the suggestion now is to not do any database manipulation from update callbacks, then what is the recommended way to bring in external assets using template icon views? If this isn't possible anymore, than it seems this layout element is a lot less useful. {F9180709} **Exact steps for others to reproduce the error** * Extract the above zip file and open append_obj_undo_crash_from_template_icon_view.blend * Run the script * In the 3d view sidebar, a new panel 'Append Object' appears under the Tool tab * In the Append Object panel, click on the thumbnail, and again on the blender icon inside * the append object op was called and a cube was appended to the scene * Undo * Blender should crash!!! * Start Blender again and run the script again * This time, run the append op using the button below the thumbnail, then undo again * Blender should not crash this time

**System Information** Operating system: Linux-4.15.0-117-generic-x86_64-with-debian-buster-sid 64 Bits Graphics card: GeForce GTX 1050/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 435.21 **Blender Version** Broken: version: 2.90.1, branch: master, commit date: 2020-09-23 06:43, hash: `rB3e85bb34d0d7` Worked: 2.82 **Short description of error** This is a follow-up to https://developer.blender.org/T80217 I'm using the update callback of an enum prop to append an object from an external blend file, then link it to the master collection. This is a fairly standard procedure for addons using template icon views to "load assets". In the previous report, it was suggested to not call an operator from the update callback to prevent crashes, if the user were to undo after such an "asset load". This new report then avoids using an operator and instead uses a dedicated `append_object_function()`. Unfortunately the crash is still happening as soon as one does an undo. As in the previous report, appending using `layout.operator()` works fine. All of this worked up until 2.82 and 2.83 was the first to crash. If the suggestion now is to not do any database manipulation from update callbacks, then what is the recommended way to bring in external assets using template icon views? If this isn't possible anymore, than it seems this layout element is a lot less useful, and addons who have been building on this ability are now a serious cause of blender instability. {F9180709} **Exact steps for others to reproduce the error** * Extract the above zip file and open append_obj_undo_crash_from_template_icon_view.blend * Run the script * In the 3d view sidebar, a new panel 'Append Object' appears under the Tool tab * In the Append Object panel, click on the thumbnail, and again on the blender icon inside * the append object op was called and a cube was appended to the scene * Undo * Blender should crash!!! * Start Blender again and run the script again * This time, run the append op using the button below the thumbnail, then undo again * Blender should not crash this time

**System Information** Operating system: Linux-4.15.0-117-generic-x86_64-with-debian-buster-sid 64 Bits Graphics card: GeForce GTX 1050/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 435.21 **Blender Version** Broken: version: 2.90.1, branch: master, commit date: 2020-09-23 06:43, hash: `rB3e85bb34d0d7` Worked: 2.82 **Short description of error** This is a follow-up to https://developer.blender.org/T80217 I'm using the update callback of an enum prop to append an object from an external blend file, then link it to the master collection. This is a fairly standard procedure for addons using template icon views to "load assets". In the previous report, it was suggested to not call an operator from the update callback to prevent crashes, if the user were to undo after such an "asset load". This new report then avoids using an operator and instead uses a dedicated `append_object_function()`. Unfortunately the crash is still happening as soon as one does an undo. As in the previous report, appending using `layout.operator()` works fine. All of this worked up until 2.82 and 2.83 was the first to crash. If the suggestion now is to not do any database manipulation from update callbacks, then what is the recommended way to bring in external assets using template icon views? If this isn't possible anymore, than it seems this layout element is a lot less useful, and addons who have been building on this ability are now a serious cause of blender instability. {F9180709} **Exact steps for others to reproduce the error** * Extract the above zip file and open append_obj_undo_crash_from_template_icon_view.blend * Run the script * In the 3d view sidebar, a new panel 'Append Object' appears under the Tool tab * In the Append Object panel, click on the thumbnail, and again on the blender icon inside * the append object op was called and a cube was appended to the scene * Undo * Blender should crash!!! * Start Blender again and run the script again * This time, run the append op using the button below the thumbnail, then undo again * Blender should not crash this time