Description Andrey Loskutov 2011-12-16 17:05:07 EST

Build Identifier: 3.3, 3.4, 3.5, 3.6, 3.7, 3.8 M4

AS IS:
In FindBugs Eclipse plugin we contribute our own problem markers. So far so good. BUT as soon as we try to contribute our "Groups" to the markerSupport extension point, we get an NPE at:

!ENTRY org.eclipse.ui.workbench 4 0 2011-12-16 22:31:52.353
!MESSAGE Unable to create view ID org.eclipse.ui.views.ProblemView: An unexpected exception was thrown.
!STACK 0
java.lang.NullPointerException
	at org.eclipse.ui.views.markers.internal.MarkerGroup.addEntry(MarkerGroup.java:452)
	at org.eclipse.ui.views.markers.internal.MarkerGroup.mapAttribute(MarkerGroup.java:594)
	at org.eclipse.ui.views.markers.internal.MarkerSupportRegistry.processAttributeMappings(MarkerSupportRegistry.java:490)
	at org.eclipse.ui.views.markers.internal.MarkerSupportRegistry.postProcessExtensions(MarkerSupportRegistry.java:400)
	at org.eclipse.ui.views.markers.internal.MarkerSupportRegistry.<init>(MarkerSupportRegistry.java:222)
	at org.eclipse.ui.views.markers.internal.MarkerSupportRegistry.getInstance(MarkerSupportRegistry.java:178)
	at org.eclipse.ui.internal.views.markers.ExtendedMarkersView.init(ExtendedMarkersView.java:947)
	at org.eclipse.ui.internal.ViewReference.createPartHelper(ViewReference.java:343)
	at org.eclipse.ui.internal.ViewReference.createPart(ViewReference.java:229)

The problem exists since ever (I can trace it down to 3.3.2) and I wonder myself why I didn't reported it yet.

The problem can be reproduced:
download the latest version of FindBugs Eclipse plugin from [1], unzip it to /dropins and before starting Eclipse, uncomment the block below in the plugin.xml:


   <extension
         point="org.eclipse.ui.ide.markerSupport">
      <markerAttributeGrouping
            attribute="priority"
            defaultGroupingEntry="org.eclipse.jdt.ui.category.potential"
            markerType="edu.umd.cs.findbugs.plugin.eclipse.findbugsMarker">
         <markerAttributeMapping

               markerGroupingEntry="fb.low"
               value="0">
         </markerAttributeMapping>
         <markerAttributeMapping
               markerGroupingEntry="fb.normal"
               value="1">
         </markerAttributeMapping>
         <markerAttributeMapping
               markerGroupingEntry="fb.high"
               value="2">
         </markerAttributeMapping>
      </markerAttributeGrouping>
      <markerGroupingEntry
            id="fb.high"
            label="FindBugs Warnings (High Confidence)"
            markerGrouping="org.eclipse.jdt.ui.java_marker_category"
            priority="79">
      </markerGroupingEntry>
      <markerGroupingEntry
            id="fb.normal"
            label="FindBugs Warnings (Normal Confidence)"
            markerGrouping="org.eclipse.jdt.ui.java_marker_category"
            priority="75">
      </markerGroupingEntry>
      <markerGroupingEntry
            id="fb.low"
            label="FindBugs Warnings (Low Confidence)"
            markerGrouping="org.eclipse.jdt.ui.java_marker_category"
            priority="71">
      </markerGroupingEntry>
   </extension>

Once plugin is installed, start Eclipse, run FindBugs analysis on any Java project (it will find for sure at least one warning), go to the Problems view (if it can be opened), change the "Group By" to "Java Problem Type", verify that there is at least one "FindBugs Warnings ..." group shown.

Now close the view (this is important!) and restart Eclipse. The view settings is now saved. On the next restart if you will do "Ctrl+3" + "Problems", Problems view fail with NPE on opening. 

If you repeat the same steps BUT do NOT close the Problems view before closing Eclipse, NPE will not occur after restart.

[1] http://prdownloads.sourceforge.net/findbugs/edu.umd.cs.findbugs.plugin.eclipse_2.0.0.20111211.zip?download
or 
http://findbugs.sourceforge.net/downloads.html

Reproducible: Always