NullPointerException when using external maven installation with no user settings

Hi,

In our company, every developer share the same maven installation with the right settings.xml configured to access our maven repository manager. So, no one should ever have any ~/.m2/settings.xml file.
To reproduce the problem:

1. add an external "maven installation"
2. the global settings.xml file is automatically selected
3. set the "user settings" field to blank
4. Click OK

Then a popup shows up, displaying "Problem Occurred" with the following message:

'Invalidating Maven settings' has encountered a problem.
An internal error occurred during: "Invalidating Maven settings".".

In the Details part of the popup, there's the following text:

An internal error occurred during: "Invalidating Maven settings".
java.lang.NullPointerException

In the .log file, there's the following stack trace:
monospaced
!ENTRY org.eclipse.core.jobs 4 2 2009-01-19 11:27:48.345
!MESSAGE An internal error occurred during: "Invalidating Maven settings".
!STACK 0
java.lang.NullPointerException
at org.eclipse.core.internal.preferences.EclipsePreferences.put(EclipsePreferences.java:758)
at org.eclipse.ui.preferences.ScopedPreferenceStore.setValue(ScopedPreferenceStore.java:789)
at org.maven.ide.eclipse.embedder.MavenRuntimeManager.setUserSettingsFile(MavenRuntimeManager.java:237)
at org.maven.ide.eclipse.ui.internal.preferences.MavenInstallationsPreferencePage$1.run(MavenInstallationsPreferencePage.java:146)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)
monospaced

The workaround for this is to just copy the "global settings" field content into the "user settings" field.

Cheers.