[news.eclipse.platform] Re: Sporadic NullPointerException during disposi

[Tom Schindl <tom.schindl@xxxxxxxxxxxxxxx>]

Please file a bug - the best would be if you modify one of our snippets 
[1] to reproduce the problem.

Tom

[1]http://wiki.eclipse.org/JFaceSnippets

Florian Bartels schrieb:
> 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) 
>
> [...]