Use model compare input if possible

The implementation of 'asCompareInput' may hijacked any comparison
using model providers through the synchronize view. Even when
double-clicking on files that are part of a model, only the "git" model
would have been allowed to provide comparison input. This is a
limitation of the current synchronize model that happens when a file
from the local workspace is compared but without considering the working
copy contents (i.e. HEAD).

This commits works around the limitation by allowing the model compare
adapter to be used when possible, i.e. a comparison with the local
workspace is performed.

Bug: 393225
Also-by: Gunnar Wagenknecht <gunnar@wagenknecht.org>
Change-Id: I69c3e36b74f8eee7755a55ec9f8f4cc42149fef7

1 files changed, 44 insertions, 17 deletions

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/synchronize/GitModelSynchronizeParticipant.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/synchronize/GitModelSynchronizeParticipant.java
index 7d6a1e1f58..84b3e476ff 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/synchronize/GitModelSynchronizeParticipant.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/synchronize/GitModelSynchronizeParticipant.java
@@ -5,6 +5,11 @@
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Dariusz Luksza <dariusz@luksza.org> - initial API and implementation
+ *     Laurent Goubet <laurent.goubet@obeo.fr> - Logical Model enhancements
+ *     Gunnar Wagenknecht <gunnar@wagenknecht.org> - Logical Model enhancements
  *******************************************************************************/
 package org.eclipse.egit.ui.internal.synchronize;
 
@@ -15,6 +20,8 @@ import java.util.HashSet;
 import java.util.Set;
 
 import org.eclipse.compare.CompareNavigator;
+import org.eclipse.compare.ITypedElement;
+import org.eclipse.compare.ResourceNode;
 import org.eclipse.compare.structuremergeviewer.ICompareInput;
 import org.eclipse.core.resources.IContainer;
 import org.eclipse.core.resources.IFile;
@@ -24,13 +31,13 @@ import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.resources.mapping.ModelProvider;
 import org.eclipse.core.resources.mapping.ResourceMapping;
 import org.eclipse.core.runtime.CoreException;
-import org.eclipse.core.runtime.IAdaptable;
 import org.eclipse.core.runtime.IPath;
+import org.eclipse.core.runtime.NullProgressMonitor;
+import org.eclipse.core.runtime.Path;
 import org.eclipse.core.runtime.jobs.IJobChangeEvent;
 import org.eclipse.core.runtime.jobs.Job;
 import org.eclipse.core.runtime.jobs.JobChangeAdapter;
-import org.eclipse.core.runtime.NullProgressMonitor;
-import org.eclipse.core.runtime.Path;
+import org.eclipse.egit.core.AdapterUtils;
 import org.eclipse.egit.core.project.GitProjectData;
 import org.eclipse.egit.core.project.RepositoryMapping;
 import org.eclipse.egit.core.synchronize.GitResourceVariantTreeSubscriber;
@@ -58,8 +65,8 @@ import org.eclipse.team.ui.TeamUI;
 import org.eclipse.team.ui.synchronize.ISynchronizePageConfiguration;
 import org.eclipse.team.ui.synchronize.ModelSynchronizeParticipant;
 import org.eclipse.ui.IMemento;
-import org.eclipse.ui.PartInitException;
 import org.eclipse.ui.IWorkbenchPart;
+import org.eclipse.ui.PartInitException;
 
 /**
  * Git model synchronization participant
@@ -200,28 +207,48 @@ public class GitModelSynchronizeParticipant extends ModelSynchronizeParticipant
 	public boolean hasCompareInputFor(Object object) {
 		if (object instanceof GitModelBlob || object instanceof IFile)
 			return true;
+
 		// in Java Workspace model Java source files are passed as type
 		// CompilationUnit which can be adapted to IResource
-		if (object instanceof IAdaptable) {
-			IResource res = (IResource) ((IAdaptable) object)
-					.getAdapter(IResource.class);
-			if (res != null && res.getType() == IResource.FILE)
-				return true;
-		}
+		IResource res = AdapterUtils.adapt(object, IResource.class);
+		if (res != null && res.getType() == IResource.FILE)
+			return true;
+
+		// fallback to super ISynchronizationCompareAdapter
 		return super.hasCompareInputFor(object);
 	}
 
 	@Override
 	public ICompareInput asCompareInput(Object object) {
-		// handle file comparison in Workspace model
-		if (object instanceof IFile) {
-			IFile file = (IFile) object;
-			GitSynchronizeData gsd = gsds.getData(file.getProject());
-			if (gsd != null && !gsd.shouldIncludeLocal())
-				return getFileFromGit(gsd, file.getLocation());
+		ICompareInput compareInput = super.asCompareInput(object);
+
+		if (compareInput != null) {
+			// note, ResourceDiffCompareInput maybe returned from super;
+			// it always has the local resource on the left side!
+			// this is only ok if we are comparing with the working tree
+
+			// handle file comparison outside working tree
+			ITypedElement left = compareInput.getLeft();
+			if (left instanceof ResourceNode) {
+				// the left side can only be a resource node if
+				// we are comparing against the local working tree
+				IResource resource = ((ResourceNode) left).getResource();
+				if (resource.getType() == IResource.FILE) {
+					GitSynchronizeData gsd = gsds
+							.getData(resource.getProject());
+					if (gsd != null && !gsd.shouldIncludeLocal())
+						return getFileFromGit(gsd, resource.getLocation());
+				}
+			}
+		} else {
+			IResource resource = AdapterUtils.adapt(object, IResource.class);
+			if (resource.getType() == IResource.FILE) {
+				GitSynchronizeData gsd = gsds.getData(resource.getProject());
+				return getFileFromGit(gsd, resource.getLocation());
+			}
 		}
 
-		return super.asCompareInput(object);
+		return compareInput;
 	}
 
 	@Override