I have found an AssertionError folowing the "Direct Merge Workflow" (merge tool)
Steps
0 - Run Udig with vm -ea (enabled assertions)
1 - select the Merge Tool
2 - Select some features using a bbox
3 - uDig present the MergeView with the selected features
4 - Press the Run button
5 - Result: Fail T
This is the stacktrace
!ENTRY net.refractions.udig.ui 1 0 2012-08-14 13:25:43.824
!MESSAGE
eu.udig.tools.merge.internal.view.MergeView@155f02ff threw an exception
!STACK 0
java.lang.AssertionError
at eu.udig.tools.merge.internal.view.MergeView.addListenersTo(MergeView.java:170)
at eu.udig.tools.merge.internal.view.MergeView.setContext(MergeView.java:714)
at net.refractions.udig.project.ui.internal.FeatureEditorExtensionProcessor$FeatureEditorViewpartListener.partVisible(FeatureEditorExtensionProcessor.java:360)
at net.refractions.udig.project.ui.internal.FeatureEditorExtensionProcessor$FeatureEditorViewpartListener.partActivated(FeatureEditorExtensionProcessor.java:286)
at org.eclipse.ui.internal.PartListenerList2$1.run(PartListenerList2.java:70)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.core.runtime.Platform.run(Platform.java:888)
at org.eclipse.ui.internal.PartListenerList2.fireEvent(PartListenerList2.java:55)
at org.eclipse.ui.internal.PartListenerList2.firePartActivated(PartListenerList2.java:68)
at org.eclipse.ui.internal.PartService.firePartActivated(PartService.java:192)
at org.eclipse.ui.internal.PartService.setActivePart(PartService.java:306)
at org.eclipse.ui.internal.WWinPartService.updateActivePart(WWinPartService.java:134)
at org.eclipse.ui.internal.WWinPartService.access$0(WWinPartService.java:125)
at org.eclipse.ui.internal.WWinPartService$WWinListener.partDeactivated(WWinPartService.java:50)
at org.eclipse.ui.internal.PartListenerList2$4.run(PartListenerList2.java:115)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.core.runtime.Platform.run(Platform.java:888)
at org.eclipse.ui.internal.PartListenerList2.fireEvent(PartListenerList2.java:55)
at org.eclipse.ui.internal.PartListenerList2.firePartDeactivated(PartListenerList2.java:113)
at org.eclipse.ui.internal.PartService.firePartDeactivated(PartService.java:242)
at org.eclipse.ui.internal.PartService.setActivePart(PartService.java:300)
at org.eclipse.ui.internal.WorkbenchPagePartList.fireActivePartChanged(WorkbenchPagePartList.java:57)
at org.eclipse.ui.internal.PartList.setActivePart(PartList.java:136)
at org.eclipse.ui.internal.WorkbenchPage.setActivePart(WorkbenchPage.java:3636)
at org.eclipse.ui.internal.WorkbenchPage.requestActivation(WorkbenchPage.java:3159)
at org.eclipse.ui.internal.PartPane.requestActivation(PartPane.java:279)
at org.eclipse.ui.internal.PartPane.handleEvent(PartPane.java:237)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1258)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1282)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1263)
at org.eclipse.swt.widgets.Shell.setActiveControl(Shell.java:1580)
at org.eclipse.swt.widgets.Control.gtk_button_press_event(Control.java:2823)
at org.eclipse.swt.widgets.Control.gtk_button_press_event(Control.java:2759)
at org.eclipse.swt.widgets.Composite.gtk_button_press_event(Composite.java:681)
at org.eclipse.swt.widgets.ToolItem.gtk_button_press_event(ToolItem.java:506)
at org.eclipse.swt.widgets.Widget.windowProc(Widget.java:1731)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4408)
at org.eclipse.swt.internal.gtk.OS._gtk_main_do_event(Native Method)
at org.eclipse.swt.internal.gtk.OS.gtk_main_do_event(OS.java:8422)
at org.eclipse.swt.widgets.Display.eventProc(Display.java:1245)
at org.eclipse.swt.internal.gtk.OS._g_main_context_iteration(Native Method)
at org.eclipse.swt.internal.gtk.OS.g_main_context_iteration(OS.java:2276)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3207)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2701)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2665)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2499)
at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:679)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:668)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at net.refractions.udig.internal.ui.UDIGApplication.start(UDIGApplication.java:138)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:344)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
at org.eclipse.equinox.launcher.Main.main(Main.java:1386)
!ENTRY org.eclipse.ui 4 0 2012-08-14 13:25:44.012
!MESSAGE Unhandled event loop exception
!STACK 0
java.lang.AssertionError: inputGeom can't be null
at eu.udig.tools.geometry.internal.util.GeometryUtil.adapt(GeometryUtil.java:191)
at eu.udig.tools.merge.internal.view.MergeFeatureBuilder.buildMergeGeometry(MergeFeatureBuilder.java:594)
at eu.udig.tools.merge.internal.view.MergeFeatureBuilder.buildMergedFeature(MergeFeatureBuilder.java:284)
at eu.udig.tools.merge.internal.view.MergeView$MergeButtonAction.run(MergeView.java:574)
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.Widget.sendEvent(Widget.java:1258)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3588)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3209)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2701)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2665)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2499)
at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:679)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:668)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at net.refractions.udig.internal.ui.UDIGApplication.start(UDIGApplication.java:138)
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:344)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
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:616)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
at org.eclipse.equinox.launcher.Main.main(Main.java:1386)
* Multipolygon tests:
Test case 1 - Select features (multipolygons) using selection tools - Result Pass
Test case 2 - Select features from Table View - Result Pass
* MultiLineString Tests:
Test case 3 - Select Multilinestring features using selection tools - Expected: Feature Merge - Result Pass
Test case 4 - Select Multilinestring features from Table View - Expected: Feature Merge - Result Pass
* Multipolygon tests:
Test case 5 - Select features (multipolygons) using selection tools - Expected: Feature Merge - Result Pass
Test case 6 - Select features from Table View - Expected: Feature Merge - Result Pass
* Polygon Tests:
Test case 7 - Select overlap Polygon features using selection tools - Expected: Feature Merge with Geometry Union - Result Pass
Test case 8 - Select isolated Polygon features from Table View - Expected: merge isn't possible (run button disable) - Result Pass
* Line Tests:
Test case 9 - Select touched line features using selection tools - Expected: Feature Merge with Geometry Union - Result Pass
Test case 10 - Select isolated line features from Table View - Expected: merge isn't possible (run button disable) - Result Pass
* Point Tests:
Test case 11 - Select Point features using selection tools - Expected: merge isn't possible (run button disable) - Result Pass