Fix for IT Nexus3939.

It happened to me on local full builds, that this IT got "stuck"
and was restarting Nexus over and over again.

If you take a peek at sources, you will see it will restart Nexus as
many times as the number of "cfs" Lucene segments grow over 7. After stopping
build and inspecting workdir, I realized that in my case, Timeline has almost 20
files, but only 3 of them had "cfs" extension.

This fix simply makes "easier" to corrupt Timeline Lucene index (this is what IT actually
tests, Nexus recovering from corrupted timeline) by taking in account any Lucene segment file
_except_ the segment index (that causes other problem then index corruption)

nexus/nexus-test-harness/nexus-test-harness-its/src/test/java/org/sonatype/nexus/integrationtests/nexus3929/Nexus3929TimelineCorruptionIT.java

@@ -18,6 +18,7 @@
 
 import java.io.File;
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
 
 import org.apache.commons.io.FileUtils;
@@ -43,15 +44,15 @@ public void oncePerClassSetUp()
 
                 stopNexus();
 
-                File tl = new File( nexusWorkDir, "timeline/index" );
-                while ( FileUtils.listFiles( tl, new String[] { "cfs" }, false ).size() < 7 )
+                final File tl = new File( nexusWorkDir, "timeline/index" );
+                while ( getTimelineLuceneSegments( tl ).size() < 7 )
                 {
                     startNexus();
                     stopNexus();
                 }
 
-                @SuppressWarnings( "unchecked" )
-                List<File> cfs = new ArrayList<File>( FileUtils.listFiles( tl, new String[] { "cfs" }, false ) );
+                List<File> cfs = getTimelineLuceneSegments( tl );
+                // just delete some files to wreck the index
                 FileUtils.forceDelete( cfs.get( 0 ) );
                 FileUtils.forceDelete( cfs.get( 2 ) );
                 FileUtils.forceDelete( cfs.get( 5 ) );
@@ -61,6 +62,27 @@ public void oncePerClassSetUp()
         }
     }
 
+    protected List<File> getTimelineLuceneSegments( final File timelineLuceneIndexDirectory )
+    {
+        @SuppressWarnings( "unchecked" )
+        final List<File> luceneFiles =
+            new ArrayList<File>( FileUtils.listFiles( timelineLuceneIndexDirectory, new String[] { "cfs", "fnm", "fdt",
+                "fdx", "frm", "frq", "nrm", "prx", "tii", "tis" }, false ) );
+
+        // filter it
+        final Iterator<File> lfi = luceneFiles.iterator();
+        while ( lfi.hasNext() )
+        {
+            final File luceneFile = lfi.next();
+            if ( luceneFile.isFile() && luceneFile.getName().startsWith( "segments." ) )
+            {
+                lfi.remove();
+            }
+        }
+
+        return luceneFiles;
+    }
+
     @Test
     public void login()
         throws Exception