Not measuring some areas

[naoliv]

I saw that the measurement plugin is giving an area of < 0.001 m² for some cases.
It's reproducible with the attached example.

JOSM:

Build-Date:2016-02-21 00:01:27
Revision:9844
Is-Local-Build:true

Identification: JOSM/1.5 (9844 SVN pt_BR) Linux Debian GNU/Linux unstable (sid)
Memory Usage: 2001 MB / 3641 MB (633 MB allocated, but free)
Java version: 1.8.0_72-internal-b15, Oracle Corporation, OpenJDK 64-Bit Server VM
VM arguments: [-Dawt.useSystemAAFontSettings=on]
Dataset consistency test: No problems found

Plugins:
- AddrInterpolation (31772)
- Create_grid_of_ways (31772)
- FastDraw (31895)
- FixAddresses (31772)
- OpeningHoursEditor (31772)
- PicLayer (31895)
- SimplifyArea (31895)
- apache-commons (31895)
- buildings_tools (31895)
- download_along (31772)
- editgpx (31772)
- ejml (31895)
- geotools (31895)
- graphview (31895)
- jts (31772)
- kendzi3d (1.0.189)
- kendzi3d-jogl (41)
- kendzi3d-resources (0.0.1)
- log4j (31895)
- measurement (31895)
- merge-overlap (31967)
- opendata (32071)
- pdfimport (32019)
- photo_geotagging (31895)
- poly (31772)
- reverter (32005)
- tagging-preset-tester (31895)
- todo (29154)
- turnrestrictions (31895)
- undelete (31895)
- utilsplugin2 (32018)

[naoliv]

The area wasn't actually closed. Sorry.