Confirmed - cause found, patch not written yet.

The window is kept on screen by measuring only its main box (208 wide), never the box plus the pet wing (379), so the wing goes off the edge.

Moving it out of OPEN so the list reflects reality: this one is pinned down to exact files and lines, so what is left is writing and testing the change, not working out what is wrong.

Fixed in 751cffcb.

Cause: the code already knows the equipment window is two pieces - it computes the combined width (208 + 177 - 6 = 379 with the wing open), centres the pair on that, sizes the click blocker with it, and hit-tests 379 wide. The one place it did NOT use that number was the position clamp, which only ever required the 208px main box to stay on screen. The wing docks to the right and is 177 wide, so on the 800px canvas it was free to run 171px past the edge - clickable, but undrawable.

There was a comment there arguing the opposite, and it was right about the mechanism but wrong about the fix: two clamps that disagree DO shove the window around on their own, and the drag code enforced the same box-only bound. Clamping just the restore would have let a drag put the pair somewhere the next refresh yanked it back from. The previous author resolved that by making both ignore the wing - which is what produced this report.

Fix: the clamp and the drag bound both use the full drawn width now, so they agree and the wing stays on screen.

Retest: open the pet wing, drag the equipment window hard right, and reopen it after a relog.