Manjaro Linux, Ati mobility radeon 4650,
Broken: 2.73- hash 53ec177, also in 2.72 stable
Short description of error
Basically if you create a clone of an object (alt+d), the clone will share the original object's data. If you add a vertex color, all the clones inherit the new vertex color - both as a new entry in the list and the actual data. If you add a shape key, all the clones inherit the shape keys.
If you add a new vertex group and assign some vertices to it, only the currently edited clone will acquire the new vertex group list entry in the vertex groups list. It will share the data of that vertex group, but it will not be added as a new entry to the vertex group lists of the clones.
To reproduce this bug:
- create a monkey head
- Clone it
- Add a new vertex group to the original and assign some verts to it
- Edit the clone - its vertex group list is empty!
<adding a new vertex group does not get added to all the instances, only the currently edited one>
- Add a new vertex group to the clone and click "select", it will select the vertex group of the original.
<however the instances still share vertex group data among each other, this opens an opportunity for a colossal error of the user- to overwrite a vertex group by mistake!>
6.Rename the clone's vertex group to something
- Go back to the original - the name you gave to the vertex group of the clone is not the same as the name of the vertex group in the original
- Create some more clones and add a bunch of vertex groups to each one- name them differently.
- Now assign some verts
Data is consistent between clones, but the names of vertex groups are completely inconsistent
So as a result, the user might overwrite their vertex group, by adding a new vertex group to a clone and editing it. Little do they know, they are writing over another vertex group that is just not yet listed and named.
Exact steps for others to reproduce the error
Based on a (as simple as possible) attached .blend file with minimum amount of steps