Ever since it was added to the VSE in e49fef45ce, edge panning would
break snapping -- edge panning a strip and then bringing it back would
cause snap code to trigger at incorrect locations. This is because the
edge pan system would update the `View2D` in `t->region->v2d.cur`, but
not mouse values, and so `t->values` would end up unchanged even while
the strip was moving.
e6a557952e fixed the issue for the node editor by recalculating mouse
input values when the view changed with `transformViewUpdate()`, but
since the code was separate from VSE, that fix did not get also get
applied here.
Although the code in `view2d_edge_pan_loc_compensate()` is mostly
identical between the two and so one possibility is to move it to
`transform_generics.cc`, adapting it to allow it to be used by both
spaces, custom transform data in the node editor additionally stores and
updates a `viewrect_prev` as mentioned in e040aea7bf, which VSE custom
data does not have. Since the fix is small enough and I don't want to
risk messing with other module code, I've opted to just copy the fix
over to VSE. If further bugs crop up in the future, we can consider
combining the code.
Also fix typo in `tranformViewUpdate()`.
Pull Request: https://projects.blender.org/blender/blender/pulls/126471
9dd2d7bd75