Hm, so after looking at this with fresh eyes (after coffee), I actually think this works as intended?

So the way it seems it will always take selection into account now (in vert select mode and in face select mode)
So, if everything is unselected in editmode, you'll get wires in weightpaint as well.

In vertex select mode, wire display was independent from selection in 2.80, that changed in 2.81
2.79 did not draw wires in vertex select mode at all.

Will check if the change from 2.80 to 2.81 was an intentional one now.

In T88385#1162684, @Philipp Oeser (lichtwerk) wrote:

So the way it seems it will always take selection into account now (in vert select mode and in face select mode)

forgot to mention that after 2.81, it will also depend on selection if neither vertex nor face masking are used

• are you sure this worked differently in 2.92 vs. 2.93/3.0?

Now that I think about it, no. I edited the report after realizing that selection mattered, and because it was 2am and I was braindead, I forgot to check if the same thing is the case with earlier versions.

• are you getting the wire if everything is unselected in editmode?

Yessir, that is correct. So things work as expected when everything is deselected in editmode.

If it turns out this always worked like this then... I find it rather odd design. :D

Except for the change from 2.80 to 2.81 [in the former, wireframe was visible even with selected geometry, in the later, selection was taken into account], this seems to behave consistent across versions.

In order to have a clean report, @Demeter Dzadik (Mets), please also clarify this:

Enter Vertex Paint instead, and then it works.

It works correctly in Vertex Paint mode.

On my side, there is no difference in behavior between weight/vertex paint, please confirm.

Hmm, I could've sworn that it was always displaying the wireframe in vertex paint mode, but now that I check again, you seem to be right... Maybe I was going crazy :/ I'll update the original post with what I see happening currently.

I think the reason this may have been unintentional is because it's inconsistent with other methods of wireframe drawing, which don't take selection into account and also look a bit different.

1. overlay.show_wireframes: Draws wireframes on all objects. This takes precedent over the below options.
2. Object.show_wire: Draws wireframe on a single object(regardless of mode or selection state). This takes precedent over the below option.
3. overlay.show_paint_wire: This is the weird one. This draws wireframe only on the active object, only in vertex paint. Nothing wrong with this idea, but this is the only wire drawing method which also comes with weird behaviour depending on the masking mode and selection states:
   • Face Masking: This seems to have its own logic for edge drawing, which is unaffected by the "Show Wires" toggle. So you're left with a checkbox that does nothing, which definitely seems unintentional.
   • Vertex Masking: Draws only those edges which have both of their faces UNselected. This means you can select two vertices, and the fact that an edge has now become selected is not indicated, until you select 4 more vertices that make up 2 faces. Then the edge connecting those two faces becomes hidden. This makes no sense to me at all.
   • No Masking: Same logic as in Vertex Masking, but in this state there is no way to change the vertex selection. So the edge drawing is purely for indication. But this indication indicates nothing, because there is no functionality in this mode for which vertex selection is relevant. Again, seems unintentional.

So I would be really curious what was the intended design here.
My suggestion is that when overlay.show_paint_wire is True, just draw all edges.
Vertex and Face masking modes are the only ones where selection states matter - and they already have clear ways to indicate when a vertex or a face is selected. There is no vertex painting mode where edge selection is relevant, so selection state of edges never needs to be indicated one way or another, as it just leads to confusion.

Note: This now changed again in rB44d2479dc36f: Refactor: DRW Mesh Extractor: Join the extractors in a same loop (now it does not draw at all)

To solve this in code we need to remove the ibo.lines_paint_mask from batch.wire_loops. (Maybe creating another batch).
Personally I think it's a valid change.

This is a bug IMO. Please don't be afraid to fix