Steps to reproduce:

• Have a build job that uses the repo plugin
• Run that job where one or more projects were added/removed from the manifest
• Access that job through the Jenkins API

Behavior:

• Going directly to the build's page in Jenkins works as I expect. However, I'm using a script that accesses Jenkins through its API. When I tack on '/api/json' or '/api/xml' to the URL, I get the following exception:

Caused by: java.lang.NullPointerException
at hudson.plugins.repo.ChangeLogEntry$1.size(ChangeLogEntry.java:296)
at java.util.AbstractList$Itr.hasNext(AbstractList.java:339)
at org.kohsuke.stapler.export.Property.writeValue(Property.java:180)
at org.kohsuke.stapler.export.Property.writeValue(Property.java:136)
at org.kohsuke.stapler.export.Property.writeTo(Property.java:113)
at org.kohsuke.stapler.export.Model.writeNestedObjectTo(Model.java:179)
at org.kohsuke.stapler.export.Model.writeNestedObjectTo(Model.java:176)
at org.kohsuke.stapler.export.Property.writeValue(Property.java:231)
at org.kohsuke.stapler.export.Property.writeValue(Property.java:168)
at org.kohsuke.stapler.export.Property.writeValue(Property.java:136)
at org.kohsuke.stapler.export.Property.writeTo(Property.java:113)
at org.kohsuke.stapler.export.Model.writeNestedObjectTo(Model.java:179)
at org.kohsuke.stapler.export.Model.writeNestedObjectTo(Model.java:176)
at org.kohsuke.stapler.export.Property.writeValue(Property.java:231)
at org.kohsuke.stapler.export.Property.writeValue(Property.java:136)
at org.kohsuke.stapler.export.Property.writeTo(Property.java:113)
at org.kohsuke.stapler.export.Model.writeNestedObjectTo(Model.java:179)
at org.kohsuke.stapler.export.Model.writeNestedObjectTo(Model.java:176)
at org.kohsuke.stapler.export.Model.writeNestedObjectTo(Model.java:176)
at org.kohsuke.stapler.export.Model.writeTo(Model.java:152)
at org.kohsuke.stapler.ResponseImpl.serveExposedBean(ResponseImpl.java:200)
at hudson.model.Api.doJson(Api.java:181)
at sun.reflect.GeneratedMethodAccessor980.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:288)
at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:151)
at org.kohsuke.stapler.Function.bindAndInvokeAndServeResponse(Function.java:90)
at org.kohsuke.stapler.MetaClass$1.doDispatch(MetaClass.java:111)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:574)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:659)
at org.kohsuke.stapler.MetaClass$4.doDispatch(MetaClass.java:203)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:574)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:659)
at org.kohsuke.stapler.MetaClass$12.dispatch(MetaClass.java:384)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:574)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:659)
at org.kohsuke.stapler.MetaClass$6.doDispatch(MetaClass.java:241)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:574)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:659)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:488)
at org.kohsuke.stapler.Stapler.service(Stapler.java:162)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)

Looking at the code (git rev 3fb046cc), I see line 296 is "return modifiedFiles.size()" in this method:

@Override
public Collection<String> getAffectedPaths() {
return new AbstractList<String>() {
@Override
public String get(final int index)

{ return modifiedFiles.get(index).getPath(); }

@Override
public int size()

{ return modifiedFiles.size(); }

};
}

If modifiedFiles is null, it would cause the behavior I'm seeing. In ChangeLog.java there appear to be 2 places where null is passed in as the modifiedFiles of ChangeLogEntry - lines 125 and 133, handling manifest adds and removals.