Bug 581559 - Reorder collapsed column groups in frozen state is broken

Signed-off-by: Dirk Fauth <dirk.fauth@googlemail.com>

Change-Id: I1b86023d119adeca369bc61676784a1aadf14512
diff --git a/org.eclipse.nebula.widgets.nattable.core/src/org/eclipse/nebula/widgets/nattable/hideshow/AbstractColumnHideShowLayer.java b/org.eclipse.nebula.widgets.nattable.core/src/org/eclipse/nebula/widgets/nattable/hideshow/AbstractColumnHideShowLayer.java
index af33931..00cb873 100644
--- a/org.eclipse.nebula.widgets.nattable.core/src/org/eclipse/nebula/widgets/nattable/hideshow/AbstractColumnHideShowLayer.java
+++ b/org.eclipse.nebula.widgets.nattable.core/src/org/eclipse/nebula/widgets/nattable/hideshow/AbstractColumnHideShowLayer.java
@@ -76,6 +76,7 @@
             int[] fromPositions = reorderEvent.getBeforeFromColumnIndexes().stream()
                     .mapToInt(Integer::intValue)
                     .map(this::getColumnPositionByIndex)
+                    .filter(pos -> pos >= 0)
                     .toArray();
             Collection<Range> fromRanges = PositionUtil.getRanges(fromPositions);
 
diff --git a/org.eclipse.nebula.widgets.nattable.core/src/org/eclipse/nebula/widgets/nattable/hideshow/AbstractRowHideShowLayer.java b/org.eclipse.nebula.widgets.nattable.core/src/org/eclipse/nebula/widgets/nattable/hideshow/AbstractRowHideShowLayer.java
index 2a0ba8c..9359f8e 100644
--- a/org.eclipse.nebula.widgets.nattable.core/src/org/eclipse/nebula/widgets/nattable/hideshow/AbstractRowHideShowLayer.java
+++ b/org.eclipse.nebula.widgets.nattable.core/src/org/eclipse/nebula/widgets/nattable/hideshow/AbstractRowHideShowLayer.java
@@ -76,6 +76,7 @@
             int[] fromPositions = reorderEvent.getBeforeFromRowIndexes().stream()
                     .mapToInt(Integer::intValue)
                     .map(this::getRowPositionByIndex)
+                    .filter(pos -> pos >= 0)
                     .toArray();
             Collection<Range> fromRanges = PositionUtil.getRanges(fromPositions);