Description Andrey Loskutov 2019-05-24 07:48:45 EDT

4.12 M3, GTK 3.22

Just got an "Unhandled event loop exception" on switching Git History to a different element. Probably regression from bug 544282 and reminds me on bug 182598 (but no crash this time).

Unfortunately not yet reproducible. Looks like the UI received event with *disposed* Item *while* GTK was removing table elements.

The  notable difference I see is that after commit 10358d0bb5c033e47e01415ae3070e4f7415aa53 we iterate  over the Table elements in opposite order and set iterator only once.

May be this order change causes some different GTK event order (or new GTK events) and we see now UI events sent with a *disposed* Items. I haven't debugged this yet, but I assume that sending events for already disposed widgets is unusual.

I assume the disposed Item is coming from Table.cellDataProc(long, long, long, long, long) callback - we find that item via GTK iterator in the Table items[] array and send it in an event via Table.checkData() to clients.

Clients do not like this :-)

org.eclipse.swt.SWTException: Widget is disposed
	at org.eclipse.swt.SWT.error(SWT.java:4699)
	at org.eclipse.swt.SWT.error(SWT.java:4614)
	at org.eclipse.swt.SWT.error(SWT.java:4585)
	at org.eclipse.swt.widgets.Widget.error(Widget.java:532)
	at org.eclipse.swt.widgets.Widget.checkWidget(Widget.java:469)
	at org.eclipse.swt.widgets.Widget.getData(Widget.java:558)
	at org.eclipse.jface.viewers.StructuredViewer.associate(StructuredViewer.java:564)
	at org.eclipse.jface.viewers.AbstractTableViewer$VirtualManager.lambda$0(AbstractTableViewer.java:101)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:89)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:5874)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1400)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1426)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1409)
	at org.eclipse.swt.widgets.Table.checkData(Table.java:283)
	at org.eclipse.swt.widgets.Table.cellDataProc(Table.java:221)
	at org.eclipse.swt.widgets.Display.cellDataProc(Display.java:913)
	at org.eclipse.swt.internal.gtk.GTK._gtk_list_store_remove(Native Method)
	at org.eclipse.swt.internal.gtk.GTK.gtk_list_store_remove(GTK.java:4054)
	at org.eclipse.swt.widgets.Table.remove(Table.java:2699)
	at org.eclipse.swt.widgets.Table.setItemCount(Table.java:3661)
	at org.eclipse.jface.viewers.TableViewer.doSetItemCount(TableViewer.java:231)
	at org.eclipse.jface.viewers.AbstractTableViewer.internalVirtualRefreshAll(AbstractTableViewer.java:643)
	at org.eclipse.jface.viewers.AbstractTableViewer.internalRefresh(AbstractTableViewer.java:617)
	at org.eclipse.jface.viewers.AbstractTableViewer.internalRefresh(AbstractTableViewer.java:607)
	at org.eclipse.jface.viewers.AbstractTableViewer.lambda$0(AbstractTableViewer.java:569)
	at org.eclipse.jface.viewers.StructuredViewer.preservingSelection(StructuredViewer.java:1391)
	at org.eclipse.jface.viewers.StructuredViewer.preservingSelection(StructuredViewer.java:1352)
	at org.eclipse.jface.viewers.AbstractTableViewer.inputChanged(AbstractTableViewer.java:569)
	at org.eclipse.jface.viewers.ContentViewer.setInput(ContentViewer.java:282)
	at org.eclipse.jface.viewers.StructuredViewer.setInput(StructuredViewer.java:1629)
	at org.eclipse.egit.ui.internal.history.CommitGraphTable.setInput(CommitGraphTable.java:432)
	at org.eclipse.egit.ui.internal.history.GitHistoryPage$13.run(GitHistoryPage.java:2210)
	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:40)
	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:185)
	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:5113)