Sorry, add the same callstack two times.

-> For NB 6.0 M6:

java.lang.UnsupportedOperationException
	at
org.netbeans.modules.java.source.parsing.FileObjects$ZipFileBase.getCharContent(FileObjects.java:617)
	at
org.netbeans.modules.java.source.parsing.FileObjects$ZipFileBase.getCharContent(FileObjects.java:577)
	at com.sun.tools.javac.main.JavaCompiler.complete(JavaCompiler.java:651)
	at com.sun.tools.javac.jvm.ClassReader.fillIn(ClassReader.java:1872)
	at
org.netbeans.modules.java.source.usages.SymbolClassReader.fillInImpl(SymbolClassReader.java:154)
	at
org.netbeans.modules.java.source.usages.SymbolClassReader.fillIn(SymbolClassReader.java:133)
	at com.sun.tools.javac.jvm.ClassReader.complete(ClassReader.java:1779)
	at com.sun.tools.javac.code.Symbol.complete(Symbol.java:384)
	at com.sun.tools.javac.code.Symbol$ClassSymbol.complete(Symbol.java:760)
	at com.sun.tools.javac.jvm.ClassReader.loadClass(ClassReader.java:1954)
	at com.sun.tools.javac.comp.Resolve.loadClass(Resolve.java:842)
	at com.sun.tools.javac.comp.Resolve.findIdentInPackage(Resolve.java:1011)
	at com.sun.tools.javac.comp.Attr.selectSym(Attr.java:1934)
	at com.sun.tools.javac.comp.Attr.visitSelect(Attr.java:1848)
	at com.sun.tools.javac.tree.JCTree$JCFieldAccess.accept(JCTree.java:1526)
	at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:368)
	at com.sun.tools.javac.comp.Attr.attribType(Attr.java:398)
	at com.sun.tools.javac.comp.MemberEnter.attribImportType(MemberEnter.java:727)
	at com.sun.tools.javac.comp.MemberEnter.visitImport(MemberEnter.java:549)
	at com.sun.tools.javac.tree.JCTree$JCImport.accept(JCTree.java:493)
	at com.sun.tools.javac.comp.MemberEnter.memberEnter(MemberEnter.java:391)
	at com.sun.tools.javac.comp.MemberEnter.memberEnter(MemberEnter.java:403)
	at com.sun.tools.javac.comp.MemberEnter.visitTopLevel(MemberEnter.java:516)
	at com.sun.tools.javac.tree.JCTree$JCCompilationUnit.accept(JCTree.java:444)
	at com.sun.tools.javac.comp.MemberEnter.memberEnter(MemberEnter.java:391)
	at com.sun.tools.javac.comp.MemberEnter.complete(MemberEnter.java:865)
	at com.sun.tools.javac.code.Symbol.complete(Symbol.java:384)
	at com.sun.tools.javac.code.Symbol$ClassSymbol.complete(Symbol.java:760)
	at com.sun.tools.javac.comp.Enter.complete(Enter.java:516)
	at
org.netbeans.api.java.source.JavaSource$ErrorHandlingJavadocEnter.main(JavaSource.java:801)
	at com.sun.tools.javac.main.JavaCompiler.enterTrees(JavaCompiler.java:824)
	at com.sun.tools.javac.api.JavacTaskImpl.enter(JavacTaskImpl.java:347)
	at com.sun.tools.javac.api.JavacTaskImpl.enter(JavacTaskImpl.java:293)
	at org.netbeans.api.java.source.JavaSource.moveToPhase(JavaSource.java:863)
	at org.netbeans.api.java.source.JavaSource$CompilationJob.run(JavaSource.java:1151)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
	at java.util.concurrent.FutureTask.run(FutureTask.java:138)
	at
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
[catch] at java.lang.Thread.run(Thread.java:619)

Not a code completion bug. Reassigning for further evaluation.

*** This issue has been marked as a duplicate of 92652 ***

I fetch the latest version (from http://deadlock.nbextras.org Build 2046) and
get still the second reported exception during indexing:

java.lang.NullPointerException
	at com.sun.tools.javac.api.JavacTaskImpl.getTreeForFile(JavacTaskImpl.java:252)
	at com.sun.tools.javac.api.JavacTaskImpl.parse(JavacTaskImpl.java:224)
	at
org.netbeans.modules.java.source.usages.RepositoryUpdater.batchCompile(RepositoryUpdater.java:1400)
	at
org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker.updateFolder(RepositoryUpdater.java:1026)
	at
org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker.scanRoots(RepositoryUpdater.java:898)
	at
org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker.access$1500(RepositoryUpdater.java:606)
	at
org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker$1.run(RepositoryUpdater.java:695)
	at
org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker$1.run(RepositoryUpdater.java:632)
	at
org.netbeans.modules.java.source.usages.ClassIndexManager.writeLock(ClassIndexManager.java:49)
	at
org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker.run(RepositoryUpdater.java:629)
	at
org.netbeans.modules.java.source.usages.RepositoryUpdater$CompileWorker.run(RepositoryUpdater.java:606)
	at org.netbeans.api.java.source.JavaSource$CompilationJob.run(JavaSource.java:1107)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
	at java.util.concurrent.FutureTask.run(FutureTask.java:138)
	at
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
[catch] at java.lang.Thread.run(Thread.java:619)

OK, the UnsupportedOperationException was a duplicate. The NPE is unrelated to
UOE, I'am going to change the issue summary.

Can you attach more details? The best will be the project for which you get the
NPE. Or at least the project files. 

The project file (nbproject/project.properties + project.xml) is enough.

Checking in javac-impl.jar;
/cvs/java/external/javac-impl.jar,v  <--  javac-impl.jar
new revision: 1.34; previous revision: 1.33
done