Illustrator Divide Objects Below Modifies Objects in Locked Group

Question

I am using Illustrator CS5. As I completed portions of a complex drawing, I grouped the completed objects then locked and hid the group while I worked on other sections. Later, when applying Divide Objects Below in the same layer, the objects in the LOCKED and HIDDEN group are also cut (or "divided") if they were below the "cutting" object.

Is this supposed to happen? It is very repeatable: create a new layer. Draw some rectangles with no stroke (just fill). Select them, then control-G to group, then lock the group and hide it using the Layers panel (there is no "eyeball" but there is a padlock). Now draw then select another shape, say a rectangle that overlaps where the other objects are (even though you can't see them). Click Object->Path->Divide Objects Below. Show then unlock the hidden group and voila! the rectangles were cut by the operation.

Either I don't understand what Locking and Hiding is supposed to do, or there is a bug in Illustrator, or someone thinks this is an intuitive way for the operator to behave.

Anyone?

Answer 1

Illustrator's Help documentation states the following:

Locking objects prevents you from selecting and editing them. You can quickly lock multiple paths, groups, and sublayers by locking their parent layer.

It's hard to say if they meant it to work this way, or if this is an oversight.

Interestingly, if you don't group the objects before locking them, 'Divide Objects Below' doesn't affect them. So it's possible that the problem here is that the Divide command is causing the objects to 'ungroup', and unlock.

Obviously, locking an object means that you can't select it and then edit it, but commands like 'Divide Objects Below' don't require the objects that they affect to be selected.

If possible, lock the objects without grouping them. Or alternatively, move the objects that you don't want to be affected onto a separate layer, lock that layer, and then perform the Divide.