Context switch: fix NPE when markers are shown

[fixed] NPE in Context switch view when markers are shown

Change-Id: I0aa2e2595aa18048cf413e72f7f420ab8a336c98
Signed-off-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/c/tracecompass.incubator/org.eclipse.tracecompass.incubator/+/165021
Tested-by: Trace Compass Bot <tracecompass-bot@eclipse.org>
Reviewed-by: Christophe Bedard <bedard.christophe@gmail.com>

analyses/org.eclipse.tracecompass.incubator.kernel.ui/src/org/eclipse/tracecompass/incubator/internal/kernel/ui/views/contextswitch/ContextSwitchPresentationProvider.java

@@ -23,6 +23,7 @@
 import org.eclipse.tracecompass.tmf.ui.widgets.timegraph.StateItem;
 import org.eclipse.tracecompass.tmf.ui.widgets.timegraph.TimeGraphPresentationProvider;
 import org.eclipse.tracecompass.tmf.ui.widgets.timegraph.model.ITimeEvent;
+import org.eclipse.tracecompass.tmf.ui.widgets.timegraph.model.MarkerEvent;
 import org.eclipse.tracecompass.tmf.ui.widgets.timegraph.model.NullTimeEvent;
 import org.eclipse.tracecompass.tmf.ui.widgets.timegraph.model.TimeEvent;
 
@@ -84,6 +85,9 @@ private static State getEventState(TimeEvent event) {
 
     @Override
     public int getStateTableIndex(ITimeEvent event) {
+        if(event instanceof MarkerEvent) {
+            return TRANSPARENT;
+        }
         ContextSwitchEntry entry = (ContextSwitchEntry) event.getEntry();
         if (!entry.hasId()) {
             return TRANSPARENT;