Let staging view use submodule repos

If the staging view is linked to the selected resource and if that
resource belongs to a submodule then staging view should also run in
the context of the submodule repo. This allows to work with submodules
in a similar manner than with native git. If I want to do a commit in a
submodule repo then select a resource in that submodule repo and you can
use Staging view to prepare the commit in the submodule repo. In native
git you would "cd" to a folder containing a file from the submodule to
switch context from the containing repo to the submodule repo. In EGit
you have to select a resource from the submodule to achieve the same.

RepositoryMapping is enhanced by one method which can return a submodule
repository. In future RepositoryMapping could be further enhanced to
support git submodules in general.

Bug: 382093
Bug: 446344
Change-Id: Ie61c597c87a68da16a92cd52fea0bc5a4ff5ec28
Also-By: Stefan Lay <stefan.lay@sap.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

4 files changed, 88 insertions, 6 deletions

diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/CoreText.java b/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/CoreText.java
index 3b3885614b..e92b70be61 100644
--- a/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/CoreText.java
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/CoreText.java
@@ -178,6 +178,9 @@ public class CoreText extends NLS {
 	public static String RepositoryFinder_finding;
 
 	/** */
+	public static String RepositoryMapping_ExceptionSubmoduleWalk;
+
+	/** */
 	public static String RepositoryUtil_DirectoryIsNotGitDirectory;
 
 	/** */
diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/coretext.properties b/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/coretext.properties
index 3a480e05fa..003a867d02 100644
--- a/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/coretext.properties
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/coretext.properties
@@ -67,6 +67,7 @@ GitProjectData_saveFailed=Saving Git team provider data to {0} failed.
 
 RebaseInteractivePlan_WriteRebaseTodoFailed=Error writing Rebase-Todo-File
 RepositoryFinder_finding=Searching for associated repositories.
+RepositoryMapping_ExceptionSubmoduleWalk=Caught exception while walking submodules
 RepositoryUtil_DirectoryIsNotGitDirectory=Repository directory to configure does not look like a Git directory: {0}
 RepositoryUtil_noHead=NO-HEAD
 ResetOperation_performingReset=Performing {0} reset to {1}
diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/project/RepositoryMapping.java b/org.eclipse.egit.core/src/org/eclipse/egit/core/project/RepositoryMapping.java
index 4e4a278da3..dbafbe1b1f 100644
--- a/org.eclipse.egit.core/src/org/eclipse/egit/core/project/RepositoryMapping.java
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/project/RepositoryMapping.java
@@ -27,8 +27,12 @@ import org.eclipse.core.resources.IResource;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.Path;
+import org.eclipse.egit.core.Activator;
 import org.eclipse.egit.core.GitProvider;
+import org.eclipse.egit.core.RepositoryCache;
+import org.eclipse.egit.core.internal.CoreText;
 import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.submodule.SubmoduleWalk;
 import org.eclipse.team.core.RepositoryProvider;
 
 /**
@@ -55,6 +59,9 @@ public class RepositoryMapping {
 
 	private IContainer container;
 
+	private final RepositoryCache repositoryCache = org.eclipse.egit.core.Activator
+			.getDefault().getRepositoryCache();
+
 	/**
 	 * Construct a {@link RepositoryMapping} for a previously connected project.
 	 *
@@ -143,6 +150,49 @@ public class RepositoryMapping {
 		return db;
 	}
 
+	/**
+	 * @param res
+	 *            a resource
+	 * @return the submodule repository if the resource is contained in a git
+	 *         submodule otherwise return {@code null}. The returned repository
+	 *         instance will always be taken from the {@link RepositoryCache}
+	 *         and the caller should not call close() on it.
+	 *
+	 *         TODO add support for multiple nesting levels of submodules
+	 */
+	public synchronized Repository getSubmoduleRepository(IResource res) {
+		IPath projectRelativePath = res.getProjectRelativePath();
+		if (projectRelativePath == null)
+			return null;
+
+		String projectRelativePathStr = res.getProjectRelativePath().toString();
+		try {
+			if (SubmoduleWalk.containsGitModulesFile(db)) {
+				SubmoduleWalk sw = SubmoduleWalk.forIndex(db);
+				while (sw.next()) {
+					if (projectRelativePathStr.startsWith(sw.getPath())) {
+						Repository subRepo = sw.getRepository();
+						if (subRepo == null)
+							return null;
+
+						Repository cachedRepo = null;
+						try {
+							cachedRepo = repositoryCache
+									.lookupRepository(subRepo.getDirectory());
+						} finally {
+							subRepo.close();
+						}
+						return cachedRepo;
+					}
+				}
+			}
+		} catch (IOException e) {
+			Activator.logWarning(
+					CoreText.RepositoryMapping_ExceptionSubmoduleWalk, e);
+		}
+		return db;
+	}
+
 	synchronized void setRepository(final Repository r) {
 		db = r;
 
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/staging/StagingView.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/staging/StagingView.java
index 8cefb091ac..b6489dcb42 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/staging/StagingView.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/staging/StagingView.java
@@ -11,6 +11,7 @@ package org.eclipse.egit.ui.internal.staging;
 import static org.eclipse.egit.ui.internal.CommonUtils.runCommand;
 
 import java.io.File;
+import java.lang.reflect.InvocationTargetException;
 import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -32,6 +33,7 @@ import org.eclipse.core.runtime.IAdaptable;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.core.runtime.Path;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.core.runtime.jobs.IJobChangeEvent;
@@ -93,6 +95,8 @@ import org.eclipse.jface.action.ToolBarManager;
 import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.jface.layout.GridDataFactory;
 import org.eclipse.jface.layout.GridLayoutFactory;
+import org.eclipse.jface.operation.IRunnableWithProgress;
+import org.eclipse.jface.operation.ModalContext;
 import org.eclipse.jface.preference.IPersistentPreferenceStore;
 import org.eclipse.jface.preference.IPreferenceStore;
 import org.eclipse.jface.resource.ImageDescriptor;
@@ -1873,12 +1877,34 @@ public class StagingView extends ViewPart implements IShowInSource {
 	}
 
 	private void showResource(final IResource resource) {
-		IProject project = resource.getProject();
-		RepositoryMapping mapping = RepositoryMapping.getMapping(project);
-		if (mapping == null)
-			return;
-		if (mapping.getRepository() != currentRepository)
-			reload(mapping.getRepository());
+		Repository newRep = getRepositoryOrNestedSubmoduleRepository(resource);
+		if (newRep != null && newRep != currentRepository)
+			reload(newRep);
+	}
+
+	private Repository getRepositoryOrNestedSubmoduleRepository(
+			final IResource resource) {
+		final Repository[] repo = new Repository[1];
+		try {
+			ModalContext.run(new IRunnableWithProgress() {
+
+				public void run(IProgressMonitor monitor) {
+					IProject project = resource.getProject();
+					RepositoryMapping mapping = RepositoryMapping
+							.getMapping(project);
+					if (mapping == null)
+						return;
+					repo[0] = mapping.getSubmoduleRepository(resource);
+					if (repo[0] == null)
+						repo[0] = mapping.getRepository();
+				}
+			}, true, new NullProgressMonitor(), Display.getDefault());
+		} catch (InvocationTargetException e) {
+			// ignore
+		} catch (InterruptedException e) {
+			// ignore
+		}
+		return repo[0];
 	}
 
 	private void stage(IStructuredSelection selection) {
@@ -1906,6 +1932,8 @@ public class StagingView extends ViewPart implements IShowInSource {
 				IResource resource = AdapterUtils.adapt(element, IResource.class);
 				if (resource != null) {
 					RepositoryMapping mapping = RepositoryMapping.getMapping(resource);
+					// doesn't do anything if the current repository is a
+					// submodule of the mapped repo
 					if (mapping != null && mapping.getRepository() == currentRepository) {
 						String path = mapping.getRepoRelativePath(resource);
 						// If resource corresponds to root of working directory