Length of way sometimes not displayed in status line

[Adrian]

What steps will reproduce the problem?

1. Create a new layer.
2. Begin to draw a new way and add a few nodes to the way.

Expected: After you click to add a node, the status line shows the current length of the new way. When you move the cursor away from the node, the status line shows the current distance from the node.
What actually happens: After you click to add a node, the status line shows --. This is a regression.

3. Change to "select" mode (shortcut S).

Expected: The status line shows the length of the way (because the way remains selected).
What actually happens: The status display does not change.

4. Deselect then reselect the way.

Expected: The status line shows the length of the way.
What actually happens: As expected.

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

I don't know whether this is related to #15119. If this is relevant, I have the selection panel open and docked.

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2017-11-26 14:31:59 +0100 (Sun, 26 Nov 2017)
Build-Date:2017-11-26 13:34:54
Revision:13170
Relative:URL: ^/trunk

Identification: JOSM/1.5 (13170 en) Mac OS X 10.11.6
OS Build number: Mac OS X 10.11.6 (15G17023)
Memory Usage: 588 MB / 3641 MB (193 MB allocated, but free)
Java version: 1.8.0_152-b16, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: Display 725375437 1920x1200
Maximum Screen Size: 1920x1200
Dataset consistency test: No problems found

Plugins:
+ ImportImagePlugin (33563)
+ InfoMode (33722)
+ PicLayer (33822)
+ apache-commons (33668)
+ cadastre-fr (33922)
+ download_along (33710)
+ editgpx (33782)
+ ejml (32680)
+ geotools (33380)
+ imagery_offset_db (33774)
+ jts (32699)
+ log4j (32699)
+ measurement (33760)
+ opendata (33791)
+ poly (33570)
+ reverter (33865)
+ turnrestrictions (33780)
+ undelete (33835)
+ utilsplugin2 (33742)
+ waydownloader (33910)

Last errors/warnings:
- W: No configuration settings found.  Using hardcoded default values for all pools.

[Don-vip]

In 13177/josm:

fix #15605 - fix display of way length in status bar during way creation

[Don-vip]

In 13178/josm:

see #15605 - code cleanup