Panning is broken

[Alexander-II]

This bug occurs since r13143 revision. The previous one dev build was without it.

What steps will reproduce the problem?

1. Start JOSM
2. Download an area or enable an imagery layer
3. Press the right mouse button (ctrl + press the touchpad in my case)
4. Try to pan around

What is the expected result?

The area in JOMS moves to the same distance as the mouse pointer moved.

What happens instead?

The area has moved to the distance about in 1 to 5 times less than expected. It's impossible to do a panning.

Please provide any additional information below. Attach a screenshot if possible.

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2017-11-23 03:14:45 +0100 (Thu, 23 Nov 2017)
Build-Date:2017-11-23 02:48:20
Revision:13150
Relative:URL: ^/trunk

Identification: JOSM/1.5 (13150 ru) Mac OS X 10.13.1
OS Build number: Mac OS X 10.13.1 (17B48)
Memory Usage: 756 MB / 2276 MB (398 MB allocated, but free)
Java version: 1.8.0_151-b12, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: Display 69677504 1280x800
Maximum Screen Size: 1280x800
Dataset consistency test: No problems found

Plugins:
+ CADTools (1007)
+ FastDraw (33731)
+ PicLayer (33822)
+ apache-commons (33668)
+ buildings_tools (33735)
+ ejml (32680)
+ geotools (33380)
+ imagery_offset_db (33774)
+ jts (32699)
+ opendata (33791)
+ reltoolbox (33708)
+ reverter (33865)
+ splinex (33844)
+ tageditor (33806)
+ tagging-preset-tester (33004)
+ todo (30303)
+ turnlanes-tagging (260)
+ undelete (33835)
+ utilsplugin2 (33742)
+ wikipedia (33696)

Tagging presets:
+ https://raw.githubusercontent.com/jacobbraeutigam/JOSM_Preset_street_cabinet/master/street_cabinet.xml
+ https://josm.openstreetmap.de/josmfile?page=Presets/Crafts&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/AdvertisingPreset&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Animal_facilities&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Bus_lanes&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Communication_Towers&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Historical_Objects&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/LaneAttributes&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/public_bookcase&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Simple_Indoor_Tagging&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/ParkingLanes&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Playground_Equipment&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Towers&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Payment_Method_RU&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Manholes&zip=1
+ https://raw.githubusercontent.com/ruosm-presets/literan-moscow/master/russian_shops.xml
+ https://josm.openstreetmap.de/josmfile?page=Presets/Drinks&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/contact(socialnetworks_IMs)&zip=1
+ ${HOME}/Documents/osm/josm-presets/healthcare1.0.xml

Map paint styles:
- https://josm.openstreetmap.de/josmfile?page=Styles/Sidewalks&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Cycleways&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Styles/AdvertisingStyle&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_Streets&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Lane_and_Road_Attributes&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/LayerChecker&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Modified&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Maxspeed&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/ParkingLanes&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Styles/Bench&zip=1

Validator rules:
+ https://raw.githubusercontent.com/zetx16/Josm-validator/master/ru-housenumber.validator.mapcss
+ http://www.openrailwaymap.org/validator/openrailwaymap.validator.mapcss
+ https://raw.githubusercontent.com/stefan-a-bauer/josm-validators/master/mtb.validator.mapcss
+ https://raw.githubusercontent.com/zetx16/Josm-HnumbValidator/master/ru-housenumber.validator.mapcss
+ https://josm.openstreetmap.de/josmfile?page=Rules/MissingWeekdays&zip=1

Last errors/warnings:
- W: No configuration settings found.  Using hardcoded default values for all pools.
- W: Предупреждение: Не удалось просканировать файл 'site-svn.openstreetmap.org-_applications_editors_josm_plugins_opendata_modules.txt' на информацию о модуле. Пропущено.

[Don-vip]

In 13154/josm:

fix #13883, fix #15586 - better fix for #13883, without breaking panning on macOS

[Don-vip]

In 13159/josm:

see #13883, #15586 - avoid HeadlessException in unit tests