[news.eclipse.platform] Sporadic NullPointerException during disposing o

[Florian Bartels <f.bartels@xxxxxx>]

Hello,

disposing columns of a TableViewer sometimes results in a 
NullPointerExcpetion in getData of swt.widgets.Widget. Called by the 
ColumnViewer.
It does not happen every time. We are able to reproduce it by creating 
and disposing columns shortly after another. I' was not able to 
reproduce why the data is null there. In our project we do not set it 
manually.

An extract of the stack trace is following.

Thanks,
Florian

java.lang.NullPointerException

    at org.eclipse.swt.widgets.Widget.getData(Widget.java:554)
    at 
org.eclipse.jface.viewers.ColumnViewer.getViewerColumn(ColumnViewer.java:186)
    at 
org.eclipse.jface.viewers.AbstractTableViewer.doUpdateItem(AbstractTableViewer.java:377)
    at 
org.eclipse.jface.viewers.StructuredViewer$UpdateItemSafeRunnable.run(StructuredViewer.java:466)
    at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37)
    at org.eclipse.core.runtime.Platform.run(Platform.java:880)
    at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:48)
    at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
    at 
org.eclipse.jface.viewers.StructuredViewer.updateItem(StructuredViewer.java:2041)
    at 
org.eclipse.jface.viewers.AbstractTableViewer$1.handleEvent(AbstractTableViewer.java:84)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1003)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1027)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1012)
    at org.eclipse.swt.widgets.Table.checkData(Table.java:928)
    at org.eclipse.swt.widgets.Table.wmNotifyChild(Table.java:6292)
    at org.eclipse.swt.widgets.Control.wmNotify(Control.java:4718)
    at org.eclipse.swt.widgets.Composite.wmNotify(Composite.java:1756)
    at org.eclipse.swt.widgets.Control.WM_NOTIFY(Control.java:4348)
    at org.eclipse.swt.widgets.Control.windowProc(Control.java:3841)
    at org.eclipse.swt.widgets.Display.windowProc(Display.java:4541)
    at org.eclipse.swt.internal.win32.OS.CallWindowProcW(Native Method)
    at org.eclipse.swt.internal.win32.OS.CallWindowProc(OS.java:2274)
    at org.eclipse.swt.widgets.Table.callWindowProc(Table.java:333)
    at org.eclipse.swt.widgets.Table.callWindowProc(Table.java:199)
    at org.eclipse.swt.widgets.Control.windowProc(Control.java:3877)
    at org.eclipse.swt.widgets.Table.windowProc(Table.java:5476)
    at org.eclipse.swt.widgets.Display.windowProc(Display.java:4528)
    at org.eclipse.swt.internal.win32.OS.CallWindowProcW(Native Method)
    at org.eclipse.swt.internal.win32.OS.CallWindowProc(OS.java:2274)
    at org.eclipse.swt.widgets.Table.callWindowProc(Table.java:333)
    at org.eclipse.swt.widgets.Table.callWindowProc(Table.java:199)
    at org.eclipse.swt.widgets.Control.windowProc(Control.java:3877)
    at org.eclipse.swt.widgets.Table.windowProc(Table.java:5476)
    at org.eclipse.swt.widgets.Display.windowProc(Display.java:4528)
    at org.eclipse.swt.internal.win32.OS.CallWindowProcW(Native Method)
    at org.eclipse.swt.internal.win32.OS.CallWindowProc(OS.java:2274)
    at org.eclipse.swt.widgets.Table.callWindowProc(Table.java:205)
    at org.eclipse.swt.widgets.Table.callWindowProc(Table.java:199)
    at org.eclipse.swt.widgets.Table.windowProc(Table.java:5388)
    at org.eclipse.swt.widgets.Display.windowProc(Display.java:4541)
    at org.eclipse.swt.internal.win32.OS.CallWindowProcW(Native Method)
    at org.eclipse.swt.internal.win32.OS.CallWindowProc(OS.java:2274)
    at org.eclipse.swt.widgets.Table.callWindowProc(Table.java:333)
    at org.eclipse.swt.widgets.Table.callWindowProc(Table.java:199)
    at org.eclipse.swt.widgets.Control.windowProc(Control.java:3877)
    at org.eclipse.swt.widgets.Table.windowProc(Table.java:5476)
    at org.eclipse.swt.widgets.Display.windowProc(Display.java:4541)
    at org.eclipse.swt.internal.win32.OS.SendMessageW(Native Method)
    at org.eclipse.swt.internal.win32.OS.SendMessage(OS.java:3022)
    at org.eclipse.swt.widgets.Table.destroyItem(Table.java:1788)
    at 
org.eclipse.swt.widgets.TableColumn.destroyWidget(TableColumn.java:193)
    at org.eclipse.swt.widgets.Widget.release(Widget.java:814)
    at org.eclipse.swt.widgets.Widget.dispose(Widget.java:441)
    at 
de.fme.plantdoc.ui.listenAnzeiger.ColumnConfigurator.disposeOldColumns(ColumnConfigurator.java:200)
[...]