Patch Set 3: I would prefer that you didn't submit this

I hit this NPE on one project I tried to compare

eclipse.buildId=M20100909-0800
java.version=1.6.0_22
java.vendor=Apple Inc.
BootLoader constants: OS=macosx, ARCH=x86_64, WS=cocoa, NL=en_US
Framework arguments:  -product org.eclipse.platform.ide
Command-line arguments:  -product org.eclipse.platform.ide -data /Users/d029788/Documents/workspace/egit/../runtime-New_configuration -dev file:/Users/d029788/Documents/workspace/egit/.metadata/.plugins/org.eclipse.pde.core/EGit/dev.properties -os macosx -ws cocoa -arch x86_64 -consoleLog


Error
Wed Jan 26 22:47:44 CET 2011


java.lang.NullPointerException
at org.eclipse.egit.core.internal.storage.CommitFileRevision.<init>(CommitFileRevision.java:59)
at org.eclipse.egit.core.internal.storage.GitFileRevision.inCommit(GitFileRevision.java:50)
at org.eclipse.egit.ui.internal.dialogs.CompareTreeView.buildMaps(CompareTreeView.java:737)
at org.eclipse.egit.ui.internal.dialogs.CompareTreeView.access$25(CompareTreeView.java:614)
at org.eclipse.egit.ui.internal.dialogs.CompareTreeView$12.run(CompareTreeView.java:584)
at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:121)

When multi-selecting multiple projects the menu entry gets disabled, would be nice if this would work also (tried with set of egit projects which all reside in same repository)