In rotation-based transform operations, the rotation axis can be
determined in two ways:
1. Through "orient_axis" (X, Y or Z)
2. Through "constraint_axis"
When the axis is obtained through the constraint, "orient_axis" is
ignored, and the angle may be negated depending on the view orientation
to match the mouse movement.
However, "orient_axis" never has its angle negated. Since the default
orientation is "View", the Z axis is inverted by default, aligning with
the mouse movement but not with the constraint axis.
This causes problems in the Redo Panel because the constraint fields
are hidden in the Rotation operation, so they need to be unset for the
Axis field to work. However, if you change the value of the Rotation
field, the object may have its rotation negated unexpectedly.
This issue was partially shown in #93078. Commit c30e6a37b0 attempted
to fix it by unsetting the constraint property when the Axis was
changed. However, this solution is incomplete: if the Axis is changed
and then reverted, the negative rotation issue reappears. In addition,
it has not been implemented in all operations.
This commit resolves the issue by reverting c30e6a37b0, aligning the
behavior of "orient_axis" and "constraint_axis", and unsetting
"constraint_axis" in `saveTranform`.
A downside of this solution is that it may break operators invoked from
Python that rely on "orient_axis" as the rotation axis, as the rotation
value now needs to be negated.
Pull Request: https://projects.blender.org/blender/blender/pulls/141101
58af30f9b9