LFS: support merge/rebase/cherry-pick/diff/compare with LFS files

Respect merge=lfs and diff=lfs attributes where required to replace (in
memory) the content of LFS pointers with the actual blob content from
the LFS storage (and vice versa when staging/merging).

Does not implement general support for merge/diff attributes for any
other use case apart from LFS.

Change-Id: Ibad8875de1e0bee8fe3a1dffb1add93111534cae
Signed-off-by: Markus Duft <markus.duft@ssi-schaefer.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

25 files changed, 848 insertions, 93 deletions

diff --git a/org.eclipse.jgit.lfs.server.test/tst/org/eclipse/jgit/lfs/server/fs/CheckoutTest.java b/org.eclipse.jgit.lfs.server.test/tst/org/eclipse/jgit/lfs/server/fs/CheckoutTest.java
index ab99e94eec..df43ccf41b 100644
--- a/org.eclipse.jgit.lfs.server.test/tst/org/eclipse/jgit/lfs/server/fs/CheckoutTest.java
+++ b/org.eclipse.jgit.lfs.server.test/tst/org/eclipse/jgit/lfs/server/fs/CheckoutTest.java
@@ -51,8 +51,7 @@ import java.nio.file.Path;
 import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.junit.JGitTestUtil;
 import org.eclipse.jgit.junit.TestRepository;
-import org.eclipse.jgit.lfs.CleanFilter;
-import org.eclipse.jgit.lfs.SmudgeFilter;
+import org.eclipse.jgit.lfs.BuiltinLFS;
 import org.eclipse.jgit.lfs.lib.LongObjectId;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.lib.StoredConfig;
@@ -72,8 +71,7 @@ public class CheckoutTest extends LfsServerTest {
 	public void setup() throws Exception {
 		super.setup();
 
-		SmudgeFilter.register();
-		CleanFilter.register();
+		BuiltinLFS.register();
 
 		Path tmp = Files.createTempDirectory("jgit_test_");
 		Repository db = FileRepositoryBuilder
diff --git a/org.eclipse.jgit.lfs.server.test/tst/org/eclipse/jgit/lfs/server/fs/PushTest.java b/org.eclipse.jgit.lfs.server.test/tst/org/eclipse/jgit/lfs/server/fs/PushTest.java
index 82566f351a..b081a8ef73 100644
--- a/org.eclipse.jgit.lfs.server.test/tst/org/eclipse/jgit/lfs/server/fs/PushTest.java
+++ b/org.eclipse.jgit.lfs.server.test/tst/org/eclipse/jgit/lfs/server/fs/PushTest.java
@@ -52,8 +52,7 @@ import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.api.RemoteAddCommand;
 import org.eclipse.jgit.junit.JGitTestUtil;
 import org.eclipse.jgit.junit.TestRepository;
-import org.eclipse.jgit.lfs.CleanFilter;
-import org.eclipse.jgit.lfs.SmudgeFilter;
+import org.eclipse.jgit.lfs.BuiltinLFS;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectLoader;
@@ -84,8 +83,7 @@ public class PushTest extends LfsServerTest {
 	public void setup() throws Exception {
 		super.setup();
 
-		SmudgeFilter.register();
-		CleanFilter.register();
+		BuiltinLFS.register();
 
 		Path rtmp = Files.createTempDirectory("jgit_test_");
 		remoteDb = FileRepositoryBuilder.create(rtmp.toFile());
diff --git a/org.eclipse.jgit.lfs/.settings/.api_filters b/org.eclipse.jgit.lfs/.settings/.api_filters
index 097fd20658..f4887e272b 100644
--- a/org.eclipse.jgit.lfs/.settings/.api_filters
+++ b/org.eclipse.jgit.lfs/.settings/.api_filters
@@ -1,5 +1,13 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <component id="org.eclipse.jgit.lfs" version="2">
+    <resource path="src/org/eclipse/jgit/lfs/CleanFilter.java" type="org.eclipse.jgit.lfs.CleanFilter">
+        <filter id="421572723">
+            <message_arguments>
+                <message_argument value="org.eclipse.jgit.lfs.CleanFilter"/>
+                <message_argument value="register()"/>
+            </message_arguments>
+        </filter>
+    </resource>
     <resource path="src/org/eclipse/jgit/lfs/LfsPointer.java" type="org.eclipse.jgit.lfs.LfsPointer">
         <filter id="336658481">
             <message_arguments>
@@ -8,4 +16,12 @@
             </message_arguments>
         </filter>
     </resource>
+    <resource path="src/org/eclipse/jgit/lfs/SmudgeFilter.java" type="org.eclipse.jgit.lfs.SmudgeFilter">
+        <filter id="421572723">
+            <message_arguments>
+                <message_argument value="org.eclipse.jgit.lfs.SmudgeFilter"/>
+                <message_argument value="register()"/>
+            </message_arguments>
+        </filter>
+    </resource>
 </component>
diff --git a/org.eclipse.jgit.lfs/META-INF/MANIFEST.MF b/org.eclipse.jgit.lfs/META-INF/MANIFEST.MF
index 798fccdfc4..6d94877148 100644
--- a/org.eclipse.jgit.lfs/META-INF/MANIFEST.MF
+++ b/org.eclipse.jgit.lfs/META-INF/MANIFEST.MF
@@ -18,6 +18,7 @@ Import-Package: com.google.gson;version="[2.8.2,3.0.0)",
  org.eclipse.jgit.annotations;version="[4.11.0,4.12.0)";resolution:=optional,
  org.eclipse.jgit.api.errors;version="[4.11.0,4.12.0)",
  org.eclipse.jgit.attributes;version="[4.11.0,4.12.0)",
+ org.eclipse.jgit.diff;version="[4.11.0,4.12.0)",
  org.eclipse.jgit.errors;version="[4.11.0,4.12.0)",
  org.eclipse.jgit.hooks;version="[4.11.0,4.12.0)",
  org.eclipse.jgit.internal.storage.file;version="[4.11.0,4.12.0)",
@@ -25,6 +26,7 @@ Import-Package: com.google.gson;version="[2.8.2,3.0.0)",
  org.eclipse.jgit.nls;version="[4.11.0,4.12.0)",
  org.eclipse.jgit.revwalk;version="[4.11.0,4.12.0)",
  org.eclipse.jgit.storage.file;version="[4.11.0,4.12.0)",
+ org.eclipse.jgit.storage.pack;version="[4.11.0,4.12.0)",
  org.eclipse.jgit.transport;version="[4.11.0,4.12.0)",
  org.eclipse.jgit.transport.http;version="[4.11.0,4.12.0)",
  org.eclipse.jgit.treewalk;version="[4.11.0,4.12.0)",
diff --git a/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/BuiltinLFS.java b/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/BuiltinLFS.java
new file mode 100644
index 0000000000..e1b9e34ed5
--- /dev/null
+++ b/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/BuiltinLFS.java
@@ -0,0 +1,140 @@
+/*
+ * Copyright (C) 2017, Markus Duft <markus.duft@ssi-schaefer.com>
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.lfs;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.PrintStream;
+
+import org.eclipse.jgit.annotations.Nullable;
+import org.eclipse.jgit.attributes.Attribute;
+import org.eclipse.jgit.hooks.PrePushHook;
+import org.eclipse.jgit.lfs.lib.Constants;
+import org.eclipse.jgit.lib.ConfigConstants;
+import org.eclipse.jgit.lib.ObjectLoader;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.util.LfsFactory;
+
+/**
+ * Implementation of {@link LfsFactory}, using built-in (optional) LFS support.
+ *
+ * @since 4.11
+ */
+public class BuiltinLFS extends LfsFactory {
+
+	private BuiltinLFS() {
+		SmudgeFilter.register();
+		CleanFilter.register();
+	}
+
+	/**
+	 * Activates the built-in LFS support.
+	 */
+	public static void register() {
+		setInstance(new BuiltinLFS());
+	}
+
+	@Override
+	public boolean isAvailable() {
+		return true;
+	}
+
+	@Override
+	public ObjectLoader applySmudgeFilter(Repository db, ObjectLoader loader,
+			Attribute attribute) throws IOException {
+		if (isEnabled(db) && (attribute == null || isEnabled(db, attribute))) {
+			return LfsBlobFilter.smudgeLfsBlob(db, loader);
+		} else {
+			return loader;
+		}
+	}
+
+	@Override
+	public LfsInputStream applyCleanFilter(Repository db, InputStream input,
+			long length, Attribute attribute) throws IOException {
+		if (isEnabled(db, attribute)) {
+			return new LfsInputStream(LfsBlobFilter.cleanLfsBlob(db, input));
+		} else {
+			return new LfsInputStream(input, length);
+		}
+	}
+
+	@Override
+	public @Nullable PrePushHook getPrePushHook(Repository repo,
+			PrintStream outputStream) {
+		if (isEnabled(repo)) {
+			return new LfsPrePushHook(repo, outputStream);
+		}
+		return null;
+	}
+
+	/**
+	 * @param db
+	 *            the repository
+	 * @return whether LFS is requested for the given repo.
+	 */
+	private boolean isEnabled(Repository db) {
+		if (db == null) {
+			return false;
+		}
+		return db.getConfig().getBoolean(ConfigConstants.CONFIG_FILTER_SECTION,
+				Constants.LFS, ConfigConstants.CONFIG_KEY_USEJGITBUILTIN,
+				false);
+	}
+
+	/**
+	 * @param db
+	 *            the repository
+	 * @param attribute
+	 *            the attribute to check
+	 * @return whether LFS filter is enabled for the given .gitattribute
+	 *         attribute.
+	 */
+	private boolean isEnabled(Repository db, Attribute attribute) {
+		if (attribute == null) {
+			return false;
+		}
+		return isEnabled(db) && Constants.LFS.equals(attribute.getValue());
+	}
+
+}
diff --git a/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/CleanFilter.java b/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/CleanFilter.java
index 3e6f9961a8..fccbae7955 100644
--- a/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/CleanFilter.java
+++ b/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/CleanFilter.java
@@ -91,7 +91,7 @@ public class CleanFilter extends FilterCommand {
 	 * Registers this filter by calling
 	 * {@link FilterCommandRegistry#register(String, FilterCommandFactory)}
 	 */
-	public final static void register() {
+	static void register() {
 		FilterCommandRegistry
 				.register(org.eclipse.jgit.lib.Constants.BUILTIN_FILTER_PREFIX
 						+ Constants.ATTR_FILTER_DRIVER_PREFIX
diff --git a/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/LfsBlobFilter.java b/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/LfsBlobFilter.java
new file mode 100644
index 0000000000..a7d218f803
--- /dev/null
+++ b/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/LfsBlobFilter.java
@@ -0,0 +1,130 @@
+/*
+ * Copyright (C) 2017, Markus Duft <markus.duft@ssi-schaefer.com>
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.lfs;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import org.eclipse.jgit.lfs.lib.AnyLongObjectId;
+import org.eclipse.jgit.lib.ObjectLoader;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.util.TemporaryBuffer;
+import org.eclipse.jgit.util.TemporaryBuffer.LocalFile;
+
+/**
+ * Provides transparently either a stream to the blob or a LFS media file if
+ * managed by LFS.
+ *
+ * @since 4.11
+ */
+public class LfsBlobFilter {
+
+	/**
+	 * In case the given {@link ObjectLoader} points to a LFS pointer file
+	 * replace the loader with one pointing to the LFS media file contents.
+	 * Missing LFS files are downloaded on the fly - same logic as the smudge
+	 * filter.
+	 *
+	 * @param db
+	 *            the repo
+	 * @param loader
+	 *            the loader for the blob
+	 * @return either the original loader, or a loader for the LFS media file if
+	 *         managed by LFS. Files are downloaded on demand if required.
+	 * @throws IOException
+	 *             in case of an error
+	 */
+	public static ObjectLoader smudgeLfsBlob(Repository db, ObjectLoader loader)
+			throws IOException {
+		if (loader.getSize() > LfsPointer.SIZE_THRESHOLD) {
+			return loader;
+		}
+
+		try (InputStream is = loader.openStream()) {
+			LfsPointer ptr = LfsPointer.parseLfsPointer(is);
+			if (ptr != null) {
+				Lfs lfs = new Lfs(db);
+				AnyLongObjectId oid = ptr.getOid();
+				Path mediaFile = lfs.getMediaFile(oid);
+				if (!Files.exists(mediaFile)) {
+					SmudgeFilter.downloadLfsResource(lfs, db, ptr);
+				}
+
+				return new LfsBlobLoader(mediaFile);
+			}
+		}
+
+		return loader;
+	}
+
+	/**
+	 * Run the LFS clean filter on the given stream and return a stream to the
+	 * LFS pointer file buffer. Used when inserting objects.
+	 *
+	 * @param db
+	 *            the {@link Repository}
+	 * @param originalContent
+	 *            the {@link InputStream} to the original content
+	 * @return a {@link TemporaryBuffer} representing the LFS pointer. The
+	 *         caller is responsible to destroy the buffer.
+	 * @throws IOException
+	 *             in case of any error.
+	 */
+	public static TemporaryBuffer cleanLfsBlob(Repository db,
+			InputStream originalContent) throws IOException {
+		LocalFile buffer = new TemporaryBuffer.LocalFile(null);
+		CleanFilter f = new CleanFilter(db, originalContent, buffer);
+		try {
+			while (f.run() != -1) {
+				// loop as long as f.run() tells there is work to do
+			}
+		} catch (IOException e) {
+			buffer.destroy();
+			throw e;
+		}
+		return buffer;
+	}
+
+}
diff --git a/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/LfsBlobLoader.java b/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/LfsBlobLoader.java
new file mode 100644
index 0000000000..697ae47a68
--- /dev/null
+++ b/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/LfsBlobLoader.java
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2017, Markus Duft <markus.duft@ssi-schaefer.com>
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.lfs;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.attribute.BasicFileAttributes;
+
+import org.eclipse.jgit.errors.LargeObjectException;
+import org.eclipse.jgit.errors.MissingObjectException;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.ObjectLoader;
+import org.eclipse.jgit.lib.ObjectStream;
+import org.eclipse.jgit.storage.pack.PackConfig;
+import org.eclipse.jgit.util.IO;
+
+/**
+ * An {@link ObjectLoader} implementation that reads a media file from the LFS
+ * storage.
+ *
+ * @since 4.11
+ */
+public class LfsBlobLoader extends ObjectLoader {
+
+	private Path mediaFile;
+
+	private BasicFileAttributes attributes;
+
+	private byte[] cached;
+
+	/**
+	 * Create a loader for the LFS media file at the given path.
+	 *
+	 * @param mediaFile
+	 *            path to the file
+	 * @throws IOException
+	 *             in case of an error reading attributes
+	 */
+	public LfsBlobLoader(Path mediaFile) throws IOException {
+		this.mediaFile = mediaFile;
+		this.attributes = Files.readAttributes(mediaFile,
+				BasicFileAttributes.class);
+	}
+
+	@Override
+	public int getType() {
+		return Constants.OBJ_BLOB;
+	}
+
+	@Override
+	public long getSize() {
+		return attributes.size();
+	}
+
+	@Override
+	public byte[] getCachedBytes() throws LargeObjectException {
+		if (getSize() > PackConfig.DEFAULT_BIG_FILE_THRESHOLD) {
+			throw new LargeObjectException();
+		}
+
+		if (cached == null) {
+			try {
+				cached = IO.readFully(mediaFile.toFile());
+			} catch (IOException ioe) {
+				throw new LargeObjectException(ioe);
+			}
+		}
+		return cached;
+	}
+
+	@Override
+	public ObjectStream openStream()
+			throws MissingObjectException, IOException {
+		return new ObjectStream.Filter(getType(), getSize(),
+				Files.newInputStream(mediaFile));
+	}
+
+}
diff --git a/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/SmudgeFilter.java b/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/SmudgeFilter.java
index ae7fab83af..142e74df6a 100644
--- a/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/SmudgeFilter.java
+++ b/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/SmudgeFilter.java
@@ -100,9 +100,9 @@ public class SmudgeFilter extends FilterCommand {
 	};
 
 	/**
-	 * Registers this filter in JGit by calling
+	 * Register this filter in JGit
 	 */
-	public final static void register() {
+	static void register() {
 		FilterCommandRegistry
 				.register(org.eclipse.jgit.lib.Constants.BUILTIN_FILTER_PREFIX
 						+ Constants.ATTR_FILTER_DRIVER_PREFIX
@@ -110,8 +110,6 @@ public class SmudgeFilter extends FilterCommand {
 						FACTORY);
 	}
 
-	private Lfs lfs;
-
 	/**
 	 * Constructor for SmudgeFilter.
 	 *
@@ -126,13 +124,13 @@ public class SmudgeFilter extends FilterCommand {
 	public SmudgeFilter(Repository db, InputStream in, OutputStream out)
 			throws IOException {
 		super(in, out);
-		lfs = new Lfs(db);
+		Lfs lfs = new Lfs(db);
 		LfsPointer res = LfsPointer.parseLfsPointer(in);
 		if (res != null) {
 			AnyLongObjectId oid = res.getOid();
 			Path mediaFile = lfs.getMediaFile(oid);
 			if (!Files.exists(mediaFile)) {
-				downloadLfsResource(db, res);
+				downloadLfsResource(lfs, db, res);
 			}
 			this.in = Files.newInputStream(mediaFile);
 		}
@@ -141,6 +139,8 @@ public class SmudgeFilter extends FilterCommand {
 	/**
 	 * Download content which is hosted on a LFS server
 	 *
+	 * @param lfs
+	 *            local {@link Lfs} storage.
 	 * @param db
 	 *            the repository to work with
 	 * @param res
@@ -148,9 +148,8 @@ public class SmudgeFilter extends FilterCommand {
 	 * @return the paths of all mediafiles which have been downloaded
 	 * @throws IOException
 	 */
-	private Collection<Path> downloadLfsResource(Repository db,
-			LfsPointer... res)
-			throws IOException {
+	public static Collection<Path> downloadLfsResource(Lfs lfs, Repository db,
+			LfsPointer... res) throws IOException {
 		Collection<Path> downloadedPaths = new ArrayList<>();
 		Map<String, LfsPointer> oidStr2ptr = new HashMap<>();
 		for (LfsPointer p : res) {
diff --git a/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/lib/Constants.java b/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/lib/Constants.java
index fbfbf377bd..835d7be02b 100644
--- a/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/lib/Constants.java
+++ b/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/lib/Constants.java
@@ -56,7 +56,7 @@ import org.eclipse.jgit.lfs.internal.LfsText;
 @SuppressWarnings("nls")
 public final class Constants {
 	/**
-	 * lfs folder
+	 * lfs folder/section/filter name
 	 *
 	 * @since 4.6
 	 */
diff --git a/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Main.java b/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Main.java
index b29b097473..189a5acbf3 100644
--- a/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Main.java
+++ b/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Main.java
@@ -65,8 +65,7 @@ import java.util.concurrent.TimeUnit;
 import org.eclipse.jgit.awtui.AwtAuthenticator;
 import org.eclipse.jgit.awtui.AwtCredentialsProvider;
 import org.eclipse.jgit.errors.TransportException;
-import org.eclipse.jgit.lfs.CleanFilter;
-import org.eclipse.jgit.lfs.SmudgeFilter;
+import org.eclipse.jgit.lfs.BuiltinLFS;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.lib.RepositoryBuilder;
 import org.eclipse.jgit.pgm.internal.CLIText;
@@ -111,8 +110,7 @@ public class Main {
 	 */
 	public Main() {
 		HttpTransport.setConnectionFactory(new HttpClientConnectionFactory());
-		CleanFilter.register();
-		SmudgeFilter.register();
+		BuiltinLFS.register();
 		gcExecutor = Executors.newSingleThreadExecutor(new ThreadFactory() {
 			private final ThreadFactory baseFactory = Executors
 					.defaultThreadFactory();
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/AddCommandTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/AddCommandTest.java
index df4be4523e..7d34e0d3f4 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/AddCommandTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/AddCommandTest.java
@@ -63,8 +63,7 @@ import org.eclipse.jgit.dircache.DirCacheBuilder;
 import org.eclipse.jgit.dircache.DirCacheEntry;
 import org.eclipse.jgit.junit.JGitTestUtil;
 import org.eclipse.jgit.junit.RepositoryTestCase;
-import org.eclipse.jgit.lfs.CleanFilter;
-import org.eclipse.jgit.lfs.SmudgeFilter;
+import org.eclipse.jgit.lfs.BuiltinLFS;
 import org.eclipse.jgit.lib.ConfigConstants;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.FileMode;
@@ -92,8 +91,7 @@ public class AddCommandTest extends RepositoryTestCase {
 
 	@Override
 	public void setUp() throws Exception {
-		CleanFilter.register();
-		SmudgeFilter.register();
+		BuiltinLFS.register();
 		super.setUp();
 	}
 
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CheckoutCommandTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CheckoutCommandTest.java
index f5a9130c1c..4f0f2a7fb0 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CheckoutCommandTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CheckoutCommandTest.java
@@ -74,8 +74,7 @@ import org.eclipse.jgit.dircache.DirCache;
 import org.eclipse.jgit.dircache.DirCacheEntry;
 import org.eclipse.jgit.junit.JGitTestUtil;
 import org.eclipse.jgit.junit.RepositoryTestCase;
-import org.eclipse.jgit.lfs.CleanFilter;
-import org.eclipse.jgit.lfs.SmudgeFilter;
+import org.eclipse.jgit.lfs.BuiltinLFS;
 import org.eclipse.jgit.lib.ConfigConstants;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.Ref;
@@ -102,8 +101,7 @@ public class CheckoutCommandTest extends RepositoryTestCase {
 	@Override
 	@Before
 	public void setUp() throws Exception {
-		CleanFilter.register();
-		SmudgeFilter.register();
+		BuiltinLFS.register();
 		super.setUp();
 		git = new Git(db);
 		// commit something
diff --git a/org.eclipse.jgit/.settings/.api_filters b/org.eclipse.jgit/.settings/.api_filters
index 3adb2f9761..86c13b470f 100644
--- a/org.eclipse.jgit/.settings/.api_filters
+++ b/org.eclipse.jgit/.settings/.api_filters
@@ -1,5 +1,13 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <component id="org.eclipse.jgit" version="2">
+    <resource path="src/org/eclipse/jgit/diff/DiffEntry.java" type="org.eclipse.jgit.diff.DiffEntry">
+        <filter id="336658481">
+            <message_arguments>
+                <message_argument value="org.eclipse.jgit.diff.DiffEntry"/>
+                <message_argument value="diffAttribute"/>
+            </message_arguments>
+        </filter>
+    </resource>
     <resource path="src/org/eclipse/jgit/lib/ConfigConstants.java" type="org.eclipse.jgit.lib.ConfigConstants">
         <filter id="336658481">
             <message_arguments>
diff --git a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
index fdaee3ee01..10139f9b89 100644
--- a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
+++ b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
@@ -462,6 +462,7 @@ noHMACsupport=No {0} support: {1}
 noMergeBase=No merge base could be determined. Reason={0}. {1}
 noMergeHeadSpecified=No merge head specified
 nonBareLinkFilesNotSupported=Link files are not supported with nonbare repos
+noPathAttributesFound=No Attributes found for {0}.
 noSuchRef=no such ref
 noSuchSubmodule=no such submodule {0}
 notABoolean=Not a boolean: {0}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/blame/BlameGenerator.java b/org.eclipse.jgit/src/org/eclipse/jgit/blame/BlameGenerator.java
index e2411d6043..1ad7a3055a 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/blame/BlameGenerator.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/blame/BlameGenerator.java
@@ -303,7 +303,8 @@ public class BlameGenerator implements AutoCloseable {
 			throws IOException {
 		if (description == null)
 			description = JGitText.get().blameNotCommittedYet;
-		BlobCandidate c = new BlobCandidate(description, resultPath);
+		BlobCandidate c = new BlobCandidate(getRepository(), description,
+				resultPath);
 		c.sourceText = contents;
 		c.regionList = new Region(0, 0, contents.size());
 		remaining = contents.size();
@@ -333,7 +334,8 @@ public class BlameGenerator implements AutoCloseable {
 		if (ldr.getType() == OBJ_BLOB) {
 			if (description == null)
 				description = JGitText.get().blameNotCommittedYet;
-			BlobCandidate c = new BlobCandidate(description, resultPath);
+			BlobCandidate c = new BlobCandidate(getRepository(), description,
+					resultPath);
 			c.sourceBlob = id.toObjectId();
 			c.sourceText = new RawText(ldr.getCachedBytes(Integer.MAX_VALUE));
 			c.regionList = new Region(0, 0, c.sourceText.size());
@@ -346,7 +348,7 @@ public class BlameGenerator implements AutoCloseable {
 		if (!find(commit, resultPath))
 			return this;
 
-		Candidate c = new Candidate(commit, resultPath);
+		Candidate c = new Candidate(getRepository(), commit, resultPath);
 		c.sourceBlob = idBuf.toObjectId();
 		c.loadText(reader);
 		c.regionList = new Region(0, 0, c.sourceText.size());
@@ -430,7 +432,8 @@ public class BlameGenerator implements AutoCloseable {
 			// just pump the queue
 		}
 
-		ReverseCandidate c = new ReverseCandidate(result, resultPath);
+		ReverseCandidate c = new ReverseCandidate(getRepository(), result,
+				resultPath);
 		c.sourceBlob = idBuf.toObjectId();
 		c.loadText(reader);
 		c.regionList = new Region(0, 0, c.sourceText.size());
@@ -637,7 +640,8 @@ public class BlameGenerator implements AutoCloseable {
 			return false;
 		}
 
-		Candidate next = n.create(parent, PathFilter.create(r.getOldPath()));
+		Candidate next = n.create(getRepository(), parent,
+				PathFilter.create(r.getOldPath()));
 		next.sourceBlob = r.getOldId().toObjectId();
 		next.renameScore = r.getScore();
 		next.loadText(reader);
@@ -653,7 +657,7 @@ public class BlameGenerator implements AutoCloseable {
 
 	private boolean splitBlameWithParent(Candidate n, RevCommit parent)
 			throws IOException {
-		Candidate next = n.create(parent, n.sourcePath);
+		Candidate next = n.create(getRepository(), parent, n.sourcePath);
 		next.sourceBlob = idBuf.toObjectId();
 		next.loadText(reader);
 		return split(next, n);
@@ -740,12 +744,12 @@ public class BlameGenerator implements AutoCloseable {
 
 			Candidate p;
 			if (renames != null && renames[pIdx] != null) {
-				p = n.create(parent,
+				p = n.create(getRepository(), parent,
 						PathFilter.create(renames[pIdx].getOldPath()));
 				p.renameScore = renames[pIdx].getScore();
 				p.sourceBlob = renames[pIdx].getOldId().toObjectId();
 			} else if (ids != null && ids[pIdx] != null) {
-				p = n.create(parent, n.sourcePath);
+				p = n.create(getRepository(), parent, n.sourcePath);
 				p.sourceBlob = ids[pIdx];
 			} else {
 				continue;
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/blame/Candidate.java b/org.eclipse.jgit/src/org/eclipse/jgit/blame/Candidate.java
index 855ef78252..457d1d2cea 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/blame/Candidate.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/blame/Candidate.java
@@ -55,10 +55,12 @@ import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectLoader;
 import org.eclipse.jgit.lib.ObjectReader;
 import org.eclipse.jgit.lib.PersonIdent;
+import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevFlag;
 import org.eclipse.jgit.revwalk.RevWalk;
 import org.eclipse.jgit.treewalk.filter.PathFilter;
+import org.eclipse.jgit.util.LfsFactory;
 
 /**
  * A source that may have supplied some (or all) of the result file.
@@ -109,7 +111,11 @@ class Candidate {
 	 */
 	int renameScore;
 
-	Candidate(RevCommit commit, PathFilter path) {
+	/** repository used for LFS blob handling */
+	private Repository sourceRepository;
+
+	Candidate(Repository repo, RevCommit commit, PathFilter path) {
+		sourceRepository = repo;
 		sourceCommit = commit;
 		sourcePath = path;
 	}
@@ -150,12 +156,12 @@ class Candidate {
 		return sourceCommit.getAuthorIdent();
 	}
 
-	Candidate create(RevCommit commit, PathFilter path) {
-		return new Candidate(commit, path);
+	Candidate create(Repository repo, RevCommit commit, PathFilter path) {
+		return new Candidate(repo, commit, path);
 	}
 
 	Candidate copy(RevCommit commit) {
-		Candidate r = create(commit, sourcePath);
+		Candidate r = create(sourceRepository, commit, sourcePath);
 		r.sourceBlob = sourceBlob;
 		r.sourceText = sourceText;
 		r.regionList = regionList;
@@ -164,7 +170,11 @@ class Candidate {
 	}
 
 	void loadText(ObjectReader reader) throws IOException {
-		ObjectLoader ldr = reader.open(sourceBlob, Constants.OBJ_BLOB);
+		ObjectLoader ldr = LfsFactory.getInstance().applySmudgeFilter(sourceRepository,
+				reader.open(sourceBlob, Constants.OBJ_BLOB),
+				LfsFactory.getAttributesForPath(sourceRepository,
+						sourcePath.getPath(), sourceCommit)
+						.get(Constants.ATTR_DIFF));
 		sourceText = new RawText(ldr.getCachedBytes(Integer.MAX_VALUE));
 	}
 
@@ -349,8 +359,9 @@ class Candidate {
 	 * children pointers, allowing reverse navigation of history.
 	 */
 	static final class ReverseCandidate extends Candidate {
-		ReverseCandidate(ReverseCommit commit, PathFilter path) {
-			super(commit, path);
+		ReverseCandidate(Repository repo, ReverseCommit commit,
+				PathFilter path) {
+			super(repo, commit, path);
 		}
 
 		@Override
@@ -370,8 +381,8 @@ class Candidate {
 		}
 
 		@Override
-		Candidate create(RevCommit commit, PathFilter path) {
-			return new ReverseCandidate((ReverseCommit) commit, path);
+		Candidate create(Repository repo, RevCommit commit, PathFilter path) {
+			return new ReverseCandidate(repo, (ReverseCommit) commit, path);
 		}
 
 		@Override
@@ -400,8 +411,8 @@ class Candidate {
 		/** Author name to refer to this blob with. */
 		String description;
 
-		BlobCandidate(String name, PathFilter path) {
-			super(null, path);
+		BlobCandidate(Repository repo, String name, PathFilter path) {
+			super(repo, null, path);
 			description = name;
 		}
 
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/diff/DiffEntry.java b/org.eclipse.jgit/src/org/eclipse/jgit/diff/DiffEntry.java
index 0f5ea76519..5c8343f92c 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/diff/DiffEntry.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/diff/DiffEntry.java
@@ -48,9 +48,11 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
+import org.eclipse.jgit.attributes.Attribute;
 import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.lib.AbbreviatedObjectId;
 import org.eclipse.jgit.lib.AnyObjectId;
+import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.FileMode;
 import org.eclipse.jgit.lib.MutableObjectId;
 import org.eclipse.jgit.lib.ObjectId;
@@ -196,6 +198,11 @@ public class DiffEntry {
 			entry.newMode = walk.getFileMode(1);
 			entry.newPath = entry.oldPath = walk.getPathString();
 
+			if (walk.getAttributesNodeProvider() != null) {
+				entry.diffAttribute = walk.getAttributes()
+						.get(Constants.ATTR_DIFF);
+			}
+
 			if (treeFilterMarker != null)
 				entry.treeFilterMarks = treeFilterMarker.getMarks(walk);
 
@@ -282,6 +289,7 @@ public class DiffEntry {
 		del.newMode = FileMode.MISSING;
 		del.newPath = DiffEntry.DEV_NULL;
 		del.changeType = ChangeType.DELETE;
+		del.diffAttribute = entry.diffAttribute;
 
 		DiffEntry add = new DiffEntry();
 		add.oldId = A_ZERO;
@@ -292,6 +300,7 @@ public class DiffEntry {
 		add.newMode = entry.getNewMode();
 		add.newPath = entry.getNewPath();
 		add.changeType = ChangeType.ADD;
+		add.diffAttribute = entry.diffAttribute;
 		return Arrays.asList(del, add);
 	}
 
@@ -306,6 +315,7 @@ public class DiffEntry {
 		r.newId = dst.newId;
 		r.newMode = dst.newMode;
 		r.newPath = dst.newPath;
+		r.diffAttribute = dst.diffAttribute;
 
 		r.changeType = changeType;
 		r.score = score;
@@ -321,6 +331,13 @@ public class DiffEntry {
 	/** File name of the new (post-image). */
 	protected String newPath;
 
+	/**
+	 * diff filter attribute
+	 *
+	 * @since 4.11
+	 */
+	protected Attribute diffAttribute;
+
 	/** Old mode of the file, if described by the patch, else null. */
 	protected FileMode oldMode;
 
@@ -395,6 +412,14 @@ public class DiffEntry {
 	}
 
 	/**
+	 * @return the {@link Attribute} determining filters to be applied.
+	 * @since 4.11
+	 */
+	public Attribute getDiffAttribute() {
+		return diffAttribute;
+	}
+
+	/**
 	 * Get the old file mode
 	 *
 	 * @return the old file mode, if described in the patch
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/diff/DiffFormatter.java b/org.eclipse.jgit/src/org/eclipse/jgit/diff/DiffFormatter.java
index bf9a27bdc9..2e29b81779 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/diff/DiffFormatter.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/diff/DiffFormatter.java
@@ -98,6 +98,7 @@ import org.eclipse.jgit.treewalk.filter.IndexDiffFilter;
 import org.eclipse.jgit.treewalk.filter.NotIgnoredFilter;
 import org.eclipse.jgit.treewalk.filter.PathFilter;
 import org.eclipse.jgit.treewalk.filter.TreeFilter;
+import org.eclipse.jgit.util.LfsFactory;
 import org.eclipse.jgit.util.QuotedString;
 
 /**
@@ -141,6 +142,8 @@ public class DiffFormatter implements AutoCloseable {
 
 	private ContentSource.Pair source;
 
+	private Repository repository;
+
 	/**
 	 * Create a new formatter with a default level of context.
 	 *
@@ -172,6 +175,7 @@ public class DiffFormatter implements AutoCloseable {
 	 *            source repository holding referenced objects.
 	 */
 	public void setRepository(Repository repository) {
+		this.repository = repository;
 		setReader(repository.newObjectReader(), repository.getConfig(), true);
 	}
 
@@ -1057,7 +1061,8 @@ public class DiffFormatter implements AutoCloseable {
 				throw new AmbiguousObjectException(id, ids);
 		}
 
-		ObjectLoader ldr = source.open(side, entry);
+		ObjectLoader ldr = LfsFactory.getInstance().applySmudgeFilter(repository,
+				source.open(side, entry), entry.getDiffAttribute());
 		return RawText.load(ldr, binaryFileThreshold);
 	}
 
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/diff/RawText.java b/org.eclipse.jgit/src/org/eclipse/jgit/diff/RawText.java
index 7be1659105..1c98074930 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/diff/RawText.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/diff/RawText.java
@@ -110,6 +110,14 @@ public class RawText extends Sequence {
 		this(IO.readFully(file));
 	}
 
+	/**
+	 * @return the raw, unprocessed content read.
+	 * @since 4.11
+	 */
+	public byte[] getRawContent() {
+		return content;
+	}
+
 	/** @return total number of items in the sequence. */
 	/** {@inheritDoc} */
 	@Override
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/hooks/Hooks.java b/org.eclipse.jgit/src/org/eclipse/jgit/hooks/Hooks.java
index a5eeb64288..79395ed23f 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/hooks/Hooks.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/hooks/Hooks.java
@@ -43,13 +43,11 @@
 package org.eclipse.jgit.hooks;
 
 import java.io.PrintStream;
-import java.lang.reflect.Constructor;
 import java.text.MessageFormat;
 
 import org.eclipse.jgit.internal.JGitText;
-import org.eclipse.jgit.lib.ConfigConstants;
 import org.eclipse.jgit.lib.Repository;
-import org.eclipse.jgit.lib.StoredConfig;
+import org.eclipse.jgit.util.LfsFactory;
 
 /**
  * Factory class for instantiating supported hooks.
@@ -112,28 +110,16 @@ public class Hooks {
 	 * @since 4.2
 	 */
 	public static PrePushHook prePush(Repository repo, PrintStream outputStream) {
-		PrePushHook lfsHook = null;
-		try {
-			StoredConfig cfg = repo.getConfig();
-			if (cfg.getBoolean(ConfigConstants.CONFIG_FILTER_SECTION, "lfs", //$NON-NLS-1$
-					ConfigConstants.CONFIG_KEY_USEJGITBUILTIN, false)) {
-				@SuppressWarnings("unchecked")
-				Class<? extends PrePushHook> cls = (Class<? extends PrePushHook>) Class
-						.forName("org.eclipse.jgit.lfs.LfsPrePushHook"); //$NON-NLS-1$
-				Constructor<? extends PrePushHook> constructor = cls
-						.getConstructor(Repository.class, PrintStream.class);
-
-				lfsHook = constructor.newInstance(repo, outputStream);
-			}
-		} catch (Exception e) {
-			// no problem :) no LFS support present
-		}
-		if (lfsHook != null) {
-			if (lfsHook.isNativeHookPresent()) {
-				throw new IllegalStateException(MessageFormat
-						.format(JGitText.get().lfsHookConflict, repo));
+		if (LfsFactory.getInstance().isAvailable()) {
+			PrePushHook hook = LfsFactory.getInstance().getPrePushHook(repo,
+					outputStream);
+			if (hook != null) {
+				if (hook.isNativeHookPresent()) {
+					throw new IllegalStateException(MessageFormat
+							.format(JGitText.get().lfsHookConflict, repo));
+				}
+				return hook;
 			}
-			return lfsHook;
 		}
 		return new PrePushHook(repo, outputStream);
 	}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
index 41f0c5c433..753a7f9a8e 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
@@ -523,6 +523,7 @@ public class JGitText extends TranslationBundle {
 	/***/ public String noMergeBase;
 	/***/ public String noMergeHeadSpecified;
 	/***/ public String nonBareLinkFilesNotSupported;
+	/***/ public String noPathAttributesFound;
 	/***/ public String noSuchRef;
 	/***/ public String noSuchSubmodule;
 	/***/ public String notABoolean;
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/Constants.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/Constants.java
index d2160011be..bb85229f82 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/Constants.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/Constants.java
@@ -438,6 +438,13 @@ public final class Constants {
 	public static final String ATTR_MERGE = "merge"; //$NON-NLS-1$
 
 	/**
+	 * Diff attribute.
+	 *
+	 * @since 4.11
+	 */
+	public static final String ATTR_DIFF = "diff"; //$NON-NLS-1$
+
+	/**
 	 * Binary value for custom merger.
 	 *
 	 * @since 4.9
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/merge/ResolveMerger.java b/org.eclipse.jgit/src/org/eclipse/jgit/merge/ResolveMerger.java
index a9c139aad5..6462608f57 100755
--- a/org.eclipse.jgit/src/org/eclipse/jgit/merge/ResolveMerger.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/merge/ResolveMerger.java
@@ -87,12 +87,12 @@ import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.errors.NoWorkTreeException;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.ConfigConstants;
+import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.CoreConfig.EolStreamType;
 import org.eclipse.jgit.lib.FileMode;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectInserter;
 import org.eclipse.jgit.lib.ObjectLoader;
-import org.eclipse.jgit.lib.ObjectReader;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevTree;
 import org.eclipse.jgit.storage.pack.PackConfig;
@@ -106,6 +106,8 @@ import org.eclipse.jgit.treewalk.WorkingTreeIterator;
 import org.eclipse.jgit.treewalk.WorkingTreeOptions;
 import org.eclipse.jgit.treewalk.filter.TreeFilter;
 import org.eclipse.jgit.util.FS;
+import org.eclipse.jgit.util.LfsFactory;
+import org.eclipse.jgit.util.LfsFactory.LfsInputStream;
 import org.eclipse.jgit.util.TemporaryBuffer;
 import org.eclipse.jgit.util.io.EolStreamTypeUtil;
 
@@ -769,11 +771,12 @@ public class ResolveMerger extends ThreeWayMerger {
 				return false;
 			}
 
-			MergeResult<RawText> result = contentMerge(base, ours, theirs);
+			MergeResult<RawText> result = contentMerge(base, ours, theirs,
+					attributes);
 			if (ignoreConflicts) {
 				result.setContainsConflicts(false);
 			}
-			updateIndex(base, ours, theirs, result);
+			updateIndex(base, ours, theirs, result, attributes);
 			if (result.containsConflicts() && !ignoreConflicts)
 				unmergedPaths.add(tw.getPathString());
 			modifiedFiles.add(tw.getPathString());
@@ -781,7 +784,8 @@ public class ResolveMerger extends ThreeWayMerger {
 			// OURS or THEIRS has been deleted
 			if (((modeO != 0 && !tw.idEqual(T_BASE, T_OURS)) || (modeT != 0 && !tw
 					.idEqual(T_BASE, T_THEIRS)))) {
-				MergeResult<RawText> result = contentMerge(base, ours, theirs);
+				MergeResult<RawText> result = contentMerge(base, ours, theirs,
+						attributes);
 
 				add(tw.getRawPath(), base, DirCacheEntry.STAGE_1, 0, 0);
 				add(tw.getRawPath(), ours, DirCacheEntry.STAGE_2, 0, 0);
@@ -816,12 +820,14 @@ public class ResolveMerger extends ThreeWayMerger {
 	 * @param base
 	 * @param ours
 	 * @param theirs
+	 * @param attributes
 	 *
 	 * @return the result of the content merge
 	 * @throws IOException
 	 */
 	private MergeResult<RawText> contentMerge(CanonicalTreeParser base,
-			CanonicalTreeParser ours, CanonicalTreeParser theirs)
+			CanonicalTreeParser ours, CanonicalTreeParser theirs,
+			Attributes attributes)
 			throws IOException {
 		RawText baseText;
 		RawText ourText;
@@ -829,11 +835,11 @@ public class ResolveMerger extends ThreeWayMerger {
 
 		try {
 			baseText = base == null ? RawText.EMPTY_TEXT : getRawText(
-				base.getEntryObjectId(), reader);
+							base.getEntryObjectId(), attributes);
 			ourText = ours == null ? RawText.EMPTY_TEXT : getRawText(
-				ours.getEntryObjectId(), reader);
+							ours.getEntryObjectId(), attributes);
 			theirsText = theirs == null ? RawText.EMPTY_TEXT : getRawText(
-				theirs.getEntryObjectId(), reader);
+							theirs.getEntryObjectId(), attributes);
 		} catch (BinaryBlobException e) {
 			MergeResult<RawText> r = new MergeResult<>(Collections.<RawText>emptyList());
 			r.setContainsConflicts(true);
@@ -897,17 +903,20 @@ public class ResolveMerger extends ThreeWayMerger {
 	 * @param ours
 	 * @param theirs
 	 * @param result
+	 * @param attributes
 	 * @throws FileNotFoundException
 	 * @throws IOException
 	 */
 	private void updateIndex(CanonicalTreeParser base,
 			CanonicalTreeParser ours, CanonicalTreeParser theirs,
-			MergeResult<RawText> result) throws FileNotFoundException,
+			MergeResult<RawText> result, Attributes attributes)
+			throws FileNotFoundException,
 			IOException {
 		TemporaryBuffer rawMerged = null;
 		try {
 			rawMerged = doMerge(result);
-			File mergedFile = inCore ? null : writeMergedFile(rawMerged);
+			File mergedFile = inCore ? null
+					: writeMergedFile(rawMerged, attributes);
 			if (result.containsConflicts()) {
 				// A conflict occurred, the file will contain conflict markers
 				// the index will be populated with the three stages and the
@@ -934,7 +943,7 @@ public class ResolveMerger extends ThreeWayMerger {
 						nonNullRepo().getFS().lastModified(mergedFile));
 				dce.setLength((int) mergedFile.length());
 			}
-			dce.setObjectId(insertMergeResult(rawMerged));
+			dce.setObjectId(insertMergeResult(rawMerged, attributes));
 			builder.add(dce);
 		} finally {
 			if (rawMerged != null) {
@@ -948,11 +957,14 @@ public class ResolveMerger extends ThreeWayMerger {
 	 *
 	 * @param rawMerged
 	 *            the raw merged content
+	 * @param attributes
+	 *            the files .gitattributes entries
 	 * @return the working tree file to which the merged content was written.
 	 * @throws FileNotFoundException
 	 * @throws IOException
 	 */
-	private File writeMergedFile(TemporaryBuffer rawMerged)
+	private File writeMergedFile(TemporaryBuffer rawMerged,
+			Attributes attributes)
 			throws FileNotFoundException, IOException {
 		File workTree = nonNullRepo().getWorkTree();
 		FS fs = nonNullRepo().getFS();
@@ -963,7 +975,7 @@ public class ResolveMerger extends ThreeWayMerger {
 		}
 		EolStreamType streamType = EolStreamTypeUtil.detectStreamType(
 				OperationType.CHECKOUT_OP, workingTreeOptions,
-				tw.getAttributes());
+				attributes);
 		try (OutputStream os = EolStreamTypeUtil.wrapOutputStream(
 				new BufferedOutputStream(new FileOutputStream(of)),
 				streamType)) {
@@ -987,9 +999,13 @@ public class ResolveMerger extends ThreeWayMerger {
 		return buf;
 	}
 
-	private ObjectId insertMergeResult(TemporaryBuffer buf) throws IOException {
-		try (InputStream in = buf.openInputStream()) {
-			return getObjectInserter().insert(OBJ_BLOB, buf.length(), in);
+	private ObjectId insertMergeResult(TemporaryBuffer buf,
+			Attributes attributes) throws IOException {
+		InputStream in = buf.openInputStream();
+		try (LfsInputStream is = LfsFactory.getInstance().applyCleanFilter(
+				getRepository(), in,
+				buf.length(), attributes.get(Constants.ATTR_MERGE))) {
+			return getObjectInserter().insert(OBJ_BLOB, is.getLength(), is);
 		}
 	}
 
@@ -1021,12 +1037,15 @@ public class ResolveMerger extends ThreeWayMerger {
 		return FileMode.MISSING.getBits();
 	}
 
-	private static RawText getRawText(ObjectId id, ObjectReader reader)
+	private RawText getRawText(ObjectId id,
+			Attributes attributes)
 			throws IOException, BinaryBlobException {
 		if (id.equals(ObjectId.zeroId()))
 			return new RawText(new byte[] {});
 
-		ObjectLoader loader = reader.open(id, OBJ_BLOB);
+		ObjectLoader loader = LfsFactory.getInstance().applySmudgeFilter(
+				getRepository(), reader.open(id, OBJ_BLOB),
+				attributes.get(Constants.ATTR_MERGE));
 		int threshold = PackConfig.DEFAULT_BIG_FILE_THRESHOLD;
 		return RawText.load(loader, threshold);
 	}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/LfsFactory.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/LfsFactory.java
new file mode 100644
index 0000000000..10fe5642a5
--- /dev/null
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/LfsFactory.java
@@ -0,0 +1,284 @@
+/*
+ * Copyright (C) 2018, Markus Duft <markus.duft@ssi-schaefer.com>
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.util;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.PrintStream;
+import java.text.MessageFormat;
+
+import org.eclipse.jgit.annotations.Nullable;
+import org.eclipse.jgit.attributes.Attribute;
+import org.eclipse.jgit.attributes.Attributes;
+import org.eclipse.jgit.hooks.PrePushHook;
+import org.eclipse.jgit.internal.JGitText;
+import org.eclipse.jgit.lib.ObjectLoader;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.treewalk.FileTreeIterator;
+import org.eclipse.jgit.treewalk.TreeWalk;
+import org.eclipse.jgit.treewalk.filter.PathFilter;
+
+/**
+ * Represents an optionally present LFS support implementation
+ *
+ * @since 4.11
+ */
+public class LfsFactory {
+
+	private static LfsFactory instance = new LfsFactory();
+
+	/**
+	 * Constructor
+	 */
+	protected LfsFactory() {
+	}
+
+	/**
+	 * @return the current LFS implementation
+	 */
+	public static LfsFactory getInstance() {
+		return instance;
+	}
+
+	/**
+	 * @param instance
+	 *            register a {@link LfsFactory} instance as the
+	 *            {@link LfsFactory} implementation to use.
+	 */
+	public static void setInstance(LfsFactory instance) {
+		LfsFactory.instance = instance;
+	}
+
+	/**
+	 * @return whether LFS support is available
+	 */
+	public boolean isAvailable() {
+		return false;
+	}
+
+	/**
+	 * Apply clean filtering to the given stream, writing the file content to
+	 * the LFS storage if required and returning a stream to the LFS pointer
+	 * instead.
+	 *
+	 * @param db
+	 *            the repository
+	 * @param input
+	 *            the original input
+	 * @param length
+	 *            the expected input stream length
+	 * @param attribute
+	 *            the attribute used to check for LFS enablement (i.e. "merge",
+	 *            "diff", "filter" from .gitattributes).
+	 * @return a stream to the content that should be written to the object
+	 *         store along with the expected length of the stream. the original
+	 *         stream is not applicable.
+	 * @throws IOException
+	 *             in case of an error
+	 */
+	public LfsInputStream applyCleanFilter(Repository db,
+			InputStream input, long length, Attribute attribute)
+			throws IOException {
+		return new LfsInputStream(input, length);
+	}
+
+	/**
+	 * Apply smudge filtering to a given loader, potentially redirecting it to a
+	 * LFS blob which is downloaded on demand.
+	 *
+	 * @param db
+	 *            the repository
+	 * @param loader
+	 *            the loader for the blob
+	 * @param attribute
+	 *            the attribute used to check for LFS enablement (i.e. "merge",
+	 *            "diff", "filter" from .gitattributes).
+	 * @return a loader for the actual data of a blob, or the original loader in
+	 *         case LFS is not applicable.
+	 * @throws IOException
+	 */
+	public ObjectLoader applySmudgeFilter(Repository db,
+			ObjectLoader loader, Attribute attribute) throws IOException {
+		return loader;
+	}
+
+	/**
+	 * Retrieve a pre-push hook to be applied.
+	 *
+	 * @param repo
+	 *            the {@link Repository} the hook is applied to.
+	 * @param outputStream
+	 * @return a {@link PrePushHook} implementation or <code>null</code>
+	 */
+	public @Nullable PrePushHook getPrePushHook(Repository repo,
+			PrintStream outputStream) {
+		return null;
+	}
+
+	/**
+	 * @param db
+	 *            the repository
+	 * @param path
+	 *            the path to find attributes for
+	 * @return the {@link Attributes} for the given path.
+	 * @throws IOException
+	 *             in case of an error
+	 */
+	public static Attributes getAttributesForPath(Repository db, String path)
+			throws IOException {
+		try (TreeWalk walk = new TreeWalk(db)) {
+			walk.addTree(new FileTreeIterator(db));
+			PathFilter f = PathFilter.create(path);
+			walk.setFilter(f);
+			walk.setRecursive(false);
+			Attributes attr = null;
+			while (walk.next()) {
+				if (f.isDone(walk)) {
+					attr = walk.getAttributes();
+					break;
+				} else if (walk.isSubtree()) {
+					walk.enterSubtree();
+				}
+			}
+			if (attr == null) {
+				throw new IOException(MessageFormat
+						.format(JGitText.get().noPathAttributesFound, path));
+			}
+
+			return attr;
+		}
+	}
+
+	/**
+	 * Get attributes for given path and commit
+	 *
+	 * @param db
+	 *            the repository
+	 * @param path
+	 *            the path to find attributes for
+	 * @param commit
+	 *            the commit to inspect.
+	 * @return the {@link Attributes} for the given path.
+	 * @throws IOException
+	 *             in case of an error
+	 */
+	public static Attributes getAttributesForPath(Repository db, String path,
+			RevCommit commit) throws IOException {
+		if (commit == null) {
+			return getAttributesForPath(db, path);
+		}
+
+		try (TreeWalk walk = TreeWalk.forPath(db, path, commit.getTree())) {
+			Attributes attr = walk == null ? null : walk.getAttributes();
+			if (attr == null) {
+				throw new IOException(MessageFormat
+						.format(JGitText.get().noPathAttributesFound, path));
+			}
+
+			return attr;
+		}
+	}
+
+	/**
+	 * Encapsulate a potentially exchanged {@link InputStream} along with the
+	 * expected stream content length.
+	 */
+	public static final class LfsInputStream extends InputStream {
+		/**
+		 * The actual stream.
+		 */
+		private InputStream stream;
+
+		/**
+		 * The expected stream content length.
+		 */
+		private long length;
+
+		/**
+		 * Create a new wrapper around a certain stream
+		 *
+		 * @param stream
+		 *            the stream to wrap. the stream will be closed on
+		 *            {@link #close()}.
+		 * @param length
+		 *            the expected length of the stream
+		 */
+		public LfsInputStream(InputStream stream, long length) {
+			this.stream = stream;
+			this.length = length;
+		}
+
+		/**
+		 * Create a new wrapper around a temporary buffer.
+		 *
+		 * @param buffer
+		 *            the buffer to initialize stream and length from. The
+		 *            buffer will be destroyed on {@link #close()}
+		 * @throws IOException
+		 *             in case of an error opening the stream to the buffer.
+		 */
+		public LfsInputStream(TemporaryBuffer buffer) throws IOException {
+			this.stream = buffer.openInputStream();
+			this.length = buffer.length();
+		}
+
+		@Override
+		public void close() throws IOException {
+			stream.close();
+		}
+
+		@Override
+		public int read() throws IOException {
+			return stream.read();
+		}
+
+		/**
+		 * @return the length of the stream
+		 */
+		public long getLength() {
+			return length;
+		}
+	}
+
+}