This applies to modifiers, constraints and shape keys.
Any driver on such data was not removed with it,
leaving invalid drivers on objects.
With this patch, the drivers are removed, but animation is left untouched.
This is because animation might be reused somewhere else and we don't
want to introduce potential side effects there.
This also adds unit tests for the fixed cases
Pull Request: https://projects.blender.org/blender/blender/pulls/134511
As discussed in #105407, it can be useful to support returning
a fallback value specified by the user instead of failing the driver
if a driver variable cannot resolve its RNA path. This especially
applies to context variables referencing custom properties, since
when the object with the driver is linked into another scene, the
custom property can easily not exist there.
This patch adds an optional fallback value setting to properties
based on RNA path (including ordinary Single Property variables
due to shared code and similarity). When enabled, RNA path lookup
failures (including invalid array index) cause the fallback value
to be used instead of marking the driver invalid.
A flag is added to track when this happens for UI use. It is
also exposed to python for lint type scripts.
When the fallback value is used, the input field containing
the property RNA path that failed to resolve is highlighted in red
(identically to the case without a fallback), and the driver
can be included in the With Errors filter of the Drivers editor.
However, the channel name is not underlined in red, because
the driver as a whole evaluates successfully.
Pull Request: https://projects.blender.org/blender/blender/pulls/110135
