JOSM SVN compiled with openjdk 7 fails to start

[malenki]

What steps will reproduce the problem?

1. have OpenJDK 7 as default
2. compile JOSM from svn (I do it with ​this script)
3. start JOSM

What is the expected result?

JOSM starts

What happens instead?

JOSM reports an error (look at "additional information) and gets stuck at

$ java -jar /home/nadar/source/josm/dist/josm-custom.jar
INFO: Detected useable IPv6 network, prefering IPv6 over IPv4.
ERROR: java.lang.AssertionError: Error: Unknown projection code
java.lang.AssertionError: Error: Unknown projection code
	at org.openstreetmap.josm.gui.preferences.projection.AbstractProjectionChoice.getProjection(AbstractProjectionChoice.java:64)
	at org.openstreetmap.josm.gui.preferences.projection.ProjectionPreference.setProjection(ProjectionPreference.java:419)
	at org.openstreetmap.josm.gui.preferences.projection.ProjectionPreference.setProjection(ProjectionPreference.java:398)
	at org.openstreetmap.josm.Main.preConstructorInit(Main.java:930)
	at org.openstreetmap.josm.gui.MainApplication.main(MainApplication.java:457)
INFO: GET https://josm.openstreetmap.de/wiki/TestedVersion?format=txt -> 200

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

Java used:
java version "1.7.0_91"
OpenJDK Runtime Environment (IcedTea 2.6.3) (7u91-2.6.3-3)
OpenJDK 64-Bit Server VM (build 24.91-b01, mixed mode)

JOSM used:
r9353, blank ~/.josm

With OpenJDK 8 there are no problems.
openjdk version "1.8.0_72-internal"
OpenJDK Runtime Environment (build 1.8.0_72-internal-b05)
OpenJDK 64-Bit Server VM (build 25.72-b05, mixed mode)

Build-Date:2016-01-09 16:41:43
Revision:9353
Is-Local-Build:true

Identification: JOSM/1.5 (9353 SVN de) Linux Debian GNU/Linux unstable (sid)
Memory Usage: 123 MB / 1102 MB (92 MB allocated, but free)
Java version: 1.7.0_91-b02, Oracle Corporation, OpenJDK 64-Bit Server VM
Java package: openjdk-7-jre:amd64-7u91-2.6.3-3
VM arguments: [-Dsun.java2d.opengl=false]


Last errors/warnings:
- E: java.lang.AssertionError: Error: Unknown projection code

java.lang.AssertionError: Error: Unknown projection code
	at org.openstreetmap.josm.gui.preferences.projection.AbstractProjectionChoice.getProjection(AbstractProjectionChoice.java:64)
	at org.openstreetmap.josm.gui.preferences.projection.ProjectionPreference.setProjection(ProjectionPreference.java:419)
	at org.openstreetmap.josm.gui.preferences.projection.ProjectionPreference.setProjection(ProjectionPreference.java:398)
	at org.openstreetmap.josm.Main.preConstructorInit(Main.java:930)
	at org.openstreetmap.josm.gui.MainApplication.main(MainApplication.java:457)

[simon04]

Since r9133, JOSM can only be compiled in the repository root directory.

[simon04]

In 9357/josm:

fix #12321 - Allow JOSM to be compiled outside of repository root directory

Regression of r9133.