Order is not preserved when selecting multiple items

[ShadowFoxNixill]

What steps will reproduce the problem?

1. Create a new relation, or view an existing one.
2. Select a few things, for example a series of connected ways (in order from end to end).
3. Add them to the relation.

What is the expected result?

The ways would be in order, and all connected

What happens instead?

The ways are jumbled in an arbitrarily determined order.

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

Screenshot after selection: ​http://prntscr.com/f49h1l

Screenshot with expected order: ​http://prntscr.com/f49h75

It's worth noting that the Sort button will work if you are trying to add a series of connected ways (with some side effects, like ​http://prntscr.com/f49hse instead of ​http://prntscr.com/f49huy), but it won't work if the items you're trying to sort aren't connected ways (for example, an ordered sequence of bus stops).

Major priority as it affects the creation/alteration of any type of Route relation.

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2017-05-03 22:19:58 +0200 (Wed, 03 May 2017)
Build-Date:2017-05-04 01:33:16
Revision:12057
Relative:URL: ^/trunk

Identification: JOSM/1.5 (12057 en) Windows 10 64-Bit
Memory Usage: 242 MB / 247 MB (108 MB allocated, but free)
Java version: 1.8.0_131-b11, Oracle Corporation, Java HotSpot(TM) Client VM
Screen: \Display0 1920x1080, \Display1 1920x1080
Maximum Screen Size: 1920x1080
VM arguments: [-Djava.security.manager, -Djava.security.policy=file:<java.home>\lib\security\javaws.policy, -DtrustProxy=true, -Djnlpx.home=<java.home>\bin, -Djnlpx.origFilenameArg=%UserProfile%\AppData\LocalLow\Sun\Java\Deployment\cache\6.0\31\583aa85f-330a2f35, -Djnlpx.remove=false, -Djava.util.Arrays.useLegacyMergeSort=true, -Djnlpx.splashport=51685, -Djnlp.application.href=https://josm.openstreetmap.de/download/josm-latest.jnlp, -Djnlpx.jvm=<java.home>\bin\javaw.exe]
Dataset consistency test: No problems found

Plugins:
+ apache-commons (32994)
+ ejml (32680)
+ geotools (33042)
+ jts (32699)
+ opendata (33245)
+ turnrestrictions (33088)
+ utilsplugin2 (33212)

Tagging presets:
+ https://josm.openstreetmap.de/josmfile?page=Presets/PublicTransportOneClick&zip=1

Map paint styles:
+ https://github.com/bastik/mapcss-tools/raw/osm/mapnik2mapcss/osm-results/mapnik.zip
- https://josm.openstreetmap.de/josmfile?page=Styles/PublicTransport&zip=1
+ %UserProfile%\GoogleDrive\JOSM\publictransport.mapcss

Last errors/warnings:
- W: extended font config - overriding 'allfonts.symbol=Symbol' with 'Segoe UI Symbol'