id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
4725	Much slower selection list handling since 3102	Ldp	team	"Since r3102, there's a new and very noticeable lag when selecting many objects.

 1. Load large dataset (40-50k objects or so)
 2. Select all/many of them (CTRL-A or selection range)
 3. The map quickly indicates that they are now selected [1]
 4. Wait... wait... wait. JOSM is blocking. CPU is 100% on single core. [2]
 5. The selection list is updated, and you can continue editing.

Steps 4 and 5 are repeated, even if you add/remove a single object from your selection.

Still present in 3122.

[1] Curiously, when having many objects selected, when (de)selecting additional objects the map only updates after the long delay.

[2] On the order of 15+ seconds on my machine, with 40k objects in the selection."	defect	closed	normal		Core		fixed