Patch Set 1: I would prefer that you didn't submit this

I tried with current egit repo and this doesn't yet work properly:
- clone egit repository using egit and import projects
- open history view in egit (using current egit stable-0.9 and this changes jgit version)
- compare resulting graph in history view against the graph displayed by gitk
-> the current algorithm uses not enough lanes so that the displayed graph edges are far from being correctly displayed

click the show all branches toggle button:
-> NPE is thrown :

!ENTRY org.eclipse.ui 4 0 2010-09-11 00:34:09.786
!MESSAGE Unhandled event loop exception
!STACK 0
java.lang.NullPointerException
	at org.eclipse.egit.ui.internal.history.GitHistoryPage.inputSet(GitHistoryPage.java:1070)
	at org.eclipse.egit.ui.internal.history.GitHistoryPage.refresh(GitHistoryPage.java:959)
	at org.eclipse.egit.ui.internal.history.GitHistoryPage$3.run(GitHistoryPage.java:383)
	at org.eclipse.jface.action.Action.runWithEvent(Action.java:498)
	at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:584)
	at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:501)
	at org.eclipse.jface.action.ActionContributionItem$6.handleEvent(ActionContributionItem.java:452)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:3776)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1367)