Description Sascha Silbe 2016-05-18 16:05:11 EDT

When trying to use the "Checkout Feature" menu option, we get the following error dialog:

=== Begin ===
An error has occurred. See error log for more details.
org.eclipse.jface.viewers.TreeViewer.getStructuredSelection()Lorg/eclipse/jface/viewers/ITreeSelection;
=== End ===

And the following detailed error message in Error Log:

=== Begin ===
eclipse.buildId=4.3.0.M20130911-1000
java.version=1.7.0_45
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=en_US
Command-line arguments:  -os win32 -ws win32 -arch x86_64

Error
Wed May 18 21:52:36 CEST 2016
Problems occurred when invoking code from plug-in: "org.eclipse.jface".

java.lang.NoSuchMethodError: org.eclipse.jface.viewers.TreeViewer.getStructuredSelection()Lorg/eclipse/jface/viewers/ITreeSelection;
	at org.eclipse.egit.gitflow.ui.internal.dialogs.FilteredBranchesWidget.getSelection(FilteredBranchesWidget.java:123)
	at org.eclipse.egit.gitflow.ui.internal.dialogs.FeatureBranchSelectionDialog.checkPage(FeatureBranchSelectionDialog.java:102)
	at org.eclipse.egit.gitflow.ui.internal.dialogs.FeatureBranchSelectionDialog.access$0(FeatureBranchSelectionDialog.java:101)
	at org.eclipse.egit.gitflow.ui.internal.dialogs.FeatureBranchSelectionDialog$1.selectionChanged(FeatureBranchSelectionDialog.java:64)
	at org.eclipse.jface.viewers.Viewer$2.run(Viewer.java:164)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)
	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
	at org.eclipse.jface.viewers.Viewer.fireSelectionChanged(Viewer.java:162)
	at org.eclipse.jface.viewers.StructuredViewer.updateSelection(StructuredViewer.java:2188)
	at org.eclipse.jface.viewers.StructuredViewer.handleSelect(StructuredViewer.java:1211)
	at org.eclipse.jface.viewers.StructuredViewer$4.widgetSelected(StructuredViewer.java:1241)
	at org.eclipse.jface.util.OpenStrategy.fireSelectionEvent(OpenStrategy.java:239)
	at org.eclipse.jface.util.OpenStrategy.access$4(OpenStrategy.java:233)
	at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:403)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1057)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4170)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3759)
	at org.eclipse.jface.window.Window.runEventLoop(Window.java:826)
	at org.eclipse.jface.window.Window.open(Window.java:802)
	at org.eclipse.jface.dialogs.MessageDialog.open(MessageDialog.java:334)
	at org.eclipse.egit.gitflow.ui.internal.actions.FeatureCheckoutHandler.execute(FeatureCheckoutHandler.java:64)
	at org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:290)
	at org.eclipse.ui.internal.handlers.E4HandlerProxy.execute(E4HandlerProxy.java:90)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:56)
	at org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(InjectorImpl.java:243)
	at org.eclipse.e4.core.internal.di.InjectorImpl.invoke(InjectorImpl.java:224)
	at org.eclipse.e4.core.contexts.ContextInjectionFactory.invoke(ContextInjectionFactory.java:132)
	at org.eclipse.e4.core.commands.internal.HandlerServiceHandler.execute(HandlerServiceHandler.java:167)
	at org.eclipse.core.commands.Command.executeWithChecks(Command.java:499)
	at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:508)
	at org.eclipse.e4.core.commands.internal.HandlerServiceImpl.executeHandler(HandlerServiceImpl.java:213)
	at org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem.executeItem(HandledContributionItem.java:850)
	at org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem.handleWidgetSelection(HandledContributionItem.java:743)
	at org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem.access$7(HandledContributionItem.java:727)
	at org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem$4.handleEvent(HandledContributionItem.java:662)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1057)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4170)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3759)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1113)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:997)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:138)
	at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:610)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:567)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:354)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:181)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:636)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:591)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1450)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1426)
=== End ===

Steps to reproduce:
1. Ensure Git Flow has been initialised and there is at least one feature branch (created using Git Flow).
2. Right click on git repository -> Git Flow -> Checkout Feature, left click on a feature branch.
3. Observe the error dialog text mentioned above.
4. Observe that the OK button never gets enabled, so checking out the feature branch using Git Flow -> Checkout Feature doesn't work.
5. Examine Error Log, observe the detailed error message mentioned above.

This happens with "Eclipse Git Team Provider - Gitflow support 4.3.0.201604071810-r" inside Progress Developer Studio 4.3 (Progress OpenEdge 11.6.1), based on Eclipse Platform 4.3.1.M20130911-1000.