Merge branch 'master' into next

* master: (38 commits)
  Revert "DFS block cache: Refactor to enable parallel index loading"
  GitServlet: allow to override default error handlers
  Silence API error for new interface method ProtocolV2Hook#onObjectInfo
  transport: add object-info capability
  Ignore IllegalStateException if JVM is already shutting down
  Update orbit to R20210825222808 for 2021-09
  Update spotbugs-maven-plugin to 4.3.0
  Update ant to 1.10.11 also in pom.xml
  DFS block cache: add additional stats to DfsReaderIoStats
  Update Orbit to S20210817231813
  [gpg] Better GPG home directory determination
  FS: cleanup use of final modifier
  Ensure FS#searchPath only selects executable files
  RevWalk: getMergedInto's result is wrong on the second call
  DFS block cache: Refactor to enable parallel index loading
  [test] Create keystore with the keytool of the running JDK
  [gpg] Update to Bouncy Castle 1.69
  [test] Create keystore with the keytool of the running JDK
  [sshd] Minor code clean-up
  Support commit.template config property
  ...

Change-Id: I9f99e9a513a23c0c0d252334e79c351512d7355e

18 files changed, 498 insertions, 36 deletions

diff --git a/org.eclipse.jgit/.settings/.api_filters b/org.eclipse.jgit/.settings/.api_filters
index 14c505de01..83a83817f4 100644
--- a/org.eclipse.jgit/.settings/.api_filters
+++ b/org.eclipse.jgit/.settings/.api_filters
@@ -8,6 +8,14 @@
             </message_arguments>
         </filter>
     </resource>
+    <resource path="src/org/eclipse/jgit/transport/ProtocolV2Hook.java" type="org.eclipse.jgit.transport.ProtocolV2Hook">
+        <filter id="404000815">
+            <message_arguments>
+                <message_argument value="org.eclipse.jgit.transport.ProtocolV2Hook"/>
+                <message_argument value="onObjectInfo(ObjectInfoRequest)"/>
+            </message_arguments>
+        </filter>
+    </resource>
     <resource path="src/org/eclipse/jgit/transport/SshConstants.java" type="org.eclipse.jgit.transport.SshConstants">
         <filter id="1142947843">
             <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 33e7452d96..3acceab098 100644
--- a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
+++ b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
@@ -365,6 +365,7 @@ invalidBooleanValue=Invalid boolean value: {0}.{1}={2}
 invalidChannel=Invalid channel {0}
 invalidCommitParentNumber=Invalid commit parent number
 invalidDepth=Invalid depth: {0}
+invalidEncoding=Invalid encoding from git config i18n.commitEncoding: {0}
 invalidEncryption=Invalid encryption
 invalidExpandWildcard=ExpandFromSource on a refspec that can have mismatched wildcards does not make sense.
 invalidFilter=Invalid filter: {0}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/api/CloneCommand.java b/org.eclipse.jgit/src/org/eclipse/jgit/api/CloneCommand.java
index cf7bc1f263..3aa711455b 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/api/CloneCommand.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/api/CloneCommand.java
@@ -173,7 +173,11 @@ public class CloneCommand extends TransportCommand<CloneCommand, Git> {
 		Repository repository = init();
 		FetchResult fetchResult = null;
 		Thread cleanupHook = new Thread(() -> cleanup());
-		Runtime.getRuntime().addShutdownHook(cleanupHook);
+		try {
+			Runtime.getRuntime().addShutdownHook(cleanupHook);
+		} catch (IllegalStateException e) {
+			// ignore - the VM is already shutting down
+		}
 		try {
 			fetchResult = fetch(repository, u);
 		} catch (IOException ioe) {
@@ -197,7 +201,11 @@ public class CloneCommand extends TransportCommand<CloneCommand, Git> {
 			cleanup();
 			throw e;
 		} finally {
-			Runtime.getRuntime().removeShutdownHook(cleanupHook);
+			try {
+				Runtime.getRuntime().removeShutdownHook(cleanupHook);
+			} catch (IllegalStateException e) {
+				// ignore - the VM is already shutting down
+			}
 		}
 		if (!noCheckout) {
 			try {
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 8622e0a1a8..76340dabb3 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
@@ -393,6 +393,7 @@ public class JGitText extends TranslationBundle {
 	/***/ public String invalidChannel;
 	/***/ public String invalidCommitParentNumber;
 	/***/ public String invalidDepth;
+	/***/ public String invalidEncoding;
 	/***/ public String invalidEncryption;
 	/***/ public String invalidExpandWildcard;
 	/***/ public String invalidFilter;
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsPackFile.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsPackFile.java
index 96ca690c1c..9be3df3b17 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsPackFile.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsPackFile.java
@@ -25,6 +25,7 @@ import java.nio.ByteBuffer;
 import java.nio.channels.Channels;
 import java.text.MessageFormat;
 import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.zip.CRC32;
 import java.util.zip.DataFormatException;
 import java.util.zip.Inflater;
@@ -162,10 +163,17 @@ public final class DfsPackFile extends BlockBasedFile {
 
 			try {
 				DfsStreamKey idxKey = desc.getStreamKey(INDEX);
+				AtomicBoolean cacheHit = new AtomicBoolean(true);
 				DfsBlockCache.Ref<PackIndex> idxref = cache.getOrLoadRef(
 						idxKey,
 						REF_POSITION,
-						() -> loadPackIndex(ctx, idxKey));
+						() -> {
+							cacheHit.set(false);
+							return loadPackIndex(ctx, idxKey);
+						});
+				if (cacheHit.get()) {
+					ctx.stats.idxCacheHit++;
+				}
 				PackIndex idx = idxref.get();
 				if (index == null && idx != null) {
 					index = idx;
@@ -200,10 +208,17 @@ public final class DfsPackFile extends BlockBasedFile {
 			PackIndex idx = idx(ctx);
 			PackReverseIndex revidx = getReverseIdx(ctx);
 			DfsStreamKey bitmapKey = desc.getStreamKey(BITMAP_INDEX);
+			AtomicBoolean cacheHit = new AtomicBoolean(true);
 			DfsBlockCache.Ref<PackBitmapIndex> idxref = cache.getOrLoadRef(
 					bitmapKey,
 					REF_POSITION,
-					() -> loadBitmapIndex(ctx, bitmapKey, idx, revidx));
+					() -> {
+						cacheHit.set(false);
+						return loadBitmapIndex(ctx, bitmapKey, idx, revidx);
+					});
+			if (cacheHit.get()) {
+				ctx.stats.bitmapCacheHit++;
+			}
 			PackBitmapIndex bmidx = idxref.get();
 			if (bitmapIndex == null && bmidx != null) {
 				bitmapIndex = bmidx;
@@ -225,10 +240,17 @@ public final class DfsPackFile extends BlockBasedFile {
 			PackIndex idx = idx(ctx);
 			DfsStreamKey revKey = new DfsStreamKey.ForReverseIndex(
 					desc.getStreamKey(INDEX));
+			AtomicBoolean cacheHit = new AtomicBoolean(true);
 			DfsBlockCache.Ref<PackReverseIndex> revref = cache.getOrLoadRef(
 					revKey,
 					REF_POSITION,
-					() -> loadReverseIdx(revKey, idx));
+					() -> {
+						cacheHit.set(false);
+						return loadReverseIdx(ctx, revKey, idx);
+					});
+			if (cacheHit.get()) {
+				ctx.stats.ridxCacheHit++;
+			}
 			PackReverseIndex revidx = revref.get();
 			if (reverseIndex == null && revidx != null) {
 				reverseIndex = revidx;
@@ -1031,9 +1053,12 @@ public final class DfsPackFile extends BlockBasedFile {
 	}
 
 	private DfsBlockCache.Ref<PackReverseIndex> loadReverseIdx(
-			DfsStreamKey revKey, PackIndex idx) {
+			DfsReader ctx, DfsStreamKey revKey, PackIndex idx) {
+		ctx.stats.readReverseIdx++;
+		long start = System.nanoTime();
 		PackReverseIndex revidx = new PackReverseIndex(idx);
 		reverseIndex = revidx;
+		ctx.stats.readReverseIdxMicros += elapsedMicros(start);
 		return new DfsBlockCache.Ref<>(
 				revKey,
 				REF_POSITION,
@@ -1064,8 +1089,8 @@ public final class DfsPackFile extends BlockBasedFile {
 				bmidx = PackBitmapIndex.read(in, idx, revidx);
 			} finally {
 				size = rc.position();
-				ctx.stats.readIdxBytes += size;
-				ctx.stats.readIdxMicros += elapsedMicros(start);
+				ctx.stats.readBitmapIdxBytes += size;
+				ctx.stats.readBitmapIdxMicros += elapsedMicros(start);
 			}
 			bitmapIndex = bmidx;
 			return new DfsBlockCache.Ref<>(
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsReaderIoStats.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsReaderIoStats.java
index b7a71969b8..5c47425013 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsReaderIoStats.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsReaderIoStats.java
@@ -19,18 +19,39 @@ public class DfsReaderIoStats {
 		/** Number of times the reader explicitly called scanPacks. */
 		long scanPacks;
 
+		/** Total number of cache hits for pack indexes. */
+		long idxCacheHit;
+
+		/** Total number of cache hits for reverse indexes. */
+		long ridxCacheHit;
+
+		/** Total number of cache hits for bitmap indexes. */
+		long bitmapCacheHit;
+
 		/** Total number of complete pack indexes read into memory. */
 		long readIdx;
 
 		/** Total number of complete bitmap indexes read into memory. */
 		long readBitmap;
 
-		/** Total number of bytes read from indexes. */
+		/** Total number of reverse indexes added into memory. */
+		long readReverseIdx;
+
+		/** Total number of bytes read from pack indexes. */
 		long readIdxBytes;
 
-		/** Total microseconds spent reading pack or bitmap indexes. */
+		/** Total microseconds spent reading pack indexes. */
 		long readIdxMicros;
 
+		/** Total microseconds spent creating reverse indexes. */
+		long readReverseIdxMicros;
+
+		/** Total number of bytes read from bitmap indexes. */
+		long readBitmapIdxBytes;
+
+		/** Total microseconds spent reading bitmap indexes. */
+		long readBitmapIdxMicros;
+
 		/** Total number of block cache hits. */
 		long blockCacheHit;
 
@@ -75,6 +96,33 @@ public class DfsReaderIoStats {
 	}
 
 	/**
+	 * Get total number of pack index cache hits.
+	 *
+	 * @return total number of pack index cache hits.
+	 */
+	public long getPackIndexCacheHits() {
+		return stats.idxCacheHit;
+	}
+
+	/**
+	 * Get total number of reverse index cache hits.
+	 *
+	 * @return total number of reverse index cache hits.
+	 */
+	public long getReverseIndexCacheHits() {
+		return stats.ridxCacheHit;
+	}
+
+	/**
+	 * Get total number of bitmap index cache hits.
+	 *
+	 * @return total number of bitmap index cache hits.
+	 */
+	public long getBitmapIndexCacheHits() {
+		return stats.bitmapCacheHit;
+	}
+
+	/**
 	 * Get total number of complete pack indexes read into memory.
 	 *
 	 * @return total number of complete pack indexes read into memory.
@@ -84,6 +132,15 @@ public class DfsReaderIoStats {
 	}
 
 	/**
+	 * Get total number of times the reverse index was computed.
+	 *
+	 * @return total number of reverse index was computed.
+	 */
+	public long getReadReverseIndexCount() {
+		return stats.readReverseIdx;
+	}
+
+	/**
 	 * Get total number of complete bitmap indexes read into memory.
 	 *
 	 * @return total number of complete bitmap indexes read into memory.
@@ -93,24 +150,51 @@ public class DfsReaderIoStats {
 	}
 
 	/**
-	 * Get total number of bytes read from indexes.
+	 * Get total number of bytes read from pack indexes.
 	 *
-	 * @return total number of bytes read from indexes.
+	 * @return total number of bytes read from pack indexes.
 	 */
 	public long getReadIndexBytes() {
 		return stats.readIdxBytes;
 	}
 
 	/**
-	 * Get total microseconds spent reading pack or bitmap indexes.
+	 * Get total microseconds spent reading pack indexes.
 	 *
-	 * @return total microseconds spent reading pack or bitmap indexes.
+	 * @return total microseconds spent reading pack indexes.
 	 */
 	public long getReadIndexMicros() {
 		return stats.readIdxMicros;
 	}
 
 	/**
+	 * Get total microseconds spent creating reverse indexes.
+	 *
+	 * @return total microseconds spent creating reverse indexes.
+	 */
+	public long getReadReverseIndexMicros() {
+		return stats.readReverseIdxMicros;
+	}
+
+	/**
+	 * Get total number of bytes read from bitmap indexes.
+	 *
+	 * @return total number of bytes read from bitmap indexes.
+	 */
+	public long getReadBitmapIndexBytes() {
+		return stats.readBitmapIdxBytes;
+	}
+
+	/**
+	 * Get total microseconds spent reading bitmap indexes.
+	 *
+	 * @return total microseconds spent reading bitmap indexes.
+	 */
+	public long getReadBitmapIndexMicros() {
+		return stats.readBitmapIdxMicros;
+	}
+
+	/**
 	 * Get total number of block cache hits.
 	 *
 	 * @return total number of block cache hits.
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/CommitConfig.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/CommitConfig.java
new file mode 100644
index 0000000000..e4e7cd6e03
--- /dev/null
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/CommitConfig.java
@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2020 Julian Ruppel <julian.ruppel@sap.com>
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Distribution License v. 1.0 which is available at
+ * https://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+package org.eclipse.jgit.lib;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.nio.charset.IllegalCharsetNameException;
+import java.nio.charset.StandardCharsets;
+import java.nio.charset.UnsupportedCharsetException;
+import java.text.MessageFormat;
+import org.eclipse.jgit.annotations.Nullable;
+import org.eclipse.jgit.errors.ConfigInvalidException;
+import org.eclipse.jgit.internal.JGitText;
+import org.eclipse.jgit.lib.Config.SectionParser;
+import org.eclipse.jgit.util.FS;
+import org.eclipse.jgit.util.IO;
+import org.eclipse.jgit.util.RawParseUtils;
+
+/**
+ * The standard "commit" configuration parameters.
+ *
+ * @since 5.13
+ */
+public class CommitConfig {
+	/**
+	 * Key for {@link Config#get(SectionParser)}.
+	 */
+	public static final Config.SectionParser<CommitConfig> KEY = CommitConfig::new;
+
+	private final static Charset DEFAULT_COMMIT_MESSAGE_ENCODING = StandardCharsets.UTF_8;
+
+	private String i18nCommitEncoding;
+
+	private String commitTemplatePath;
+
+	private CommitConfig(Config rc) {
+		commitTemplatePath = rc.getString(ConfigConstants.CONFIG_COMMIT_SECTION,
+				null, ConfigConstants.CONFIG_KEY_COMMIT_TEMPLATE);
+		i18nCommitEncoding = rc.getString(ConfigConstants.CONFIG_SECTION_I18N,
+				null, ConfigConstants.CONFIG_KEY_COMMIT_ENCODING);
+	}
+
+	/**
+	 * Get the path to the commit template as defined in the git
+	 * {@code commit.template} property.
+	 *
+	 * @return the path to commit template or {@code null} if not present.
+	 */
+	@Nullable
+	public String getCommitTemplatePath() {
+		return commitTemplatePath;
+	}
+
+	/**
+	 * Get the encoding of the commit as defined in the git
+	 * {@code i18n.commitEncoding} property.
+	 *
+	 * @return the encoding or {@code null} if not present.
+	 */
+	@Nullable
+	public String getCommitEncoding() {
+		return i18nCommitEncoding;
+	}
+
+	/**
+	 * Get the content to the commit template as defined in
+	 * {@code commit.template}. If no {@code i18n.commitEncoding} is specified,
+	 * UTF-8 fallback is used.
+	 *
+	 * @return content of the commit template or {@code null} if not present.
+	 * @throws IOException
+	 *             if the template file can not be read
+	 * @throws FileNotFoundException
+	 *             if the template file does not exists
+	 * @throws ConfigInvalidException
+	 *             if a {@code commitEncoding} is specified and is invalid
+	 */
+	@Nullable
+	public String getCommitTemplateContent()
+			throws FileNotFoundException, IOException, ConfigInvalidException {
+
+		if (commitTemplatePath == null) {
+			return null;
+		}
+
+		File commitTemplateFile;
+		if (commitTemplatePath.startsWith("~/")) { //$NON-NLS-1$
+			commitTemplateFile = FS.DETECTED.resolve(FS.DETECTED.userHome(),
+					commitTemplatePath.substring(2));
+		} else {
+			commitTemplateFile = FS.DETECTED.resolve(null, commitTemplatePath);
+		}
+
+		Charset commitMessageEncoding = getEncoding();
+		return RawParseUtils.decode(commitMessageEncoding,
+				IO.readFully(commitTemplateFile));
+
+	}
+
+	private Charset getEncoding() throws ConfigInvalidException {
+		Charset commitMessageEncoding = DEFAULT_COMMIT_MESSAGE_ENCODING;
+
+		if (i18nCommitEncoding == null) {
+			return null;
+		}
+
+		try {
+			commitMessageEncoding = Charset.forName(i18nCommitEncoding);
+		} catch (IllegalCharsetNameException | UnsupportedCharsetException e) {
+			throw new ConfigInvalidException(MessageFormat.format(
+					JGitText.get().invalidEncoding, i18nCommitEncoding), e);
+		}
+
+		return commitMessageEncoding;
+	}
+}
\ No newline at end of file
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/ConfigConstants.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/ConfigConstants.java
index b6f4798dce..24eebc6a19 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/ConfigConstants.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/ConfigConstants.java
@@ -125,6 +125,13 @@ public final class ConfigConstants {
 	public static final String CONFIG_COMMIT_SECTION = "commit";
 
 	/**
+	 * The "template" key
+	 *
+	 * @since 5.13
+	 */
+	public static final String CONFIG_KEY_COMMIT_TEMPLATE = "template";
+
+	/**
 	 * The "tag" section
 	 *
 	 * @since 5.11
@@ -518,6 +525,13 @@ public final class ConfigConstants {
 	public static final String CONFIG_SECTION_I18N = "i18n";
 
 	/**
+	 * The "commitEncoding" key
+	 *
+	 * @since 5.13
+	 */
+	public static final String CONFIG_KEY_COMMIT_ENCODING = "commitEncoding";
+
+	/**
 	 * The "logOutputEncoding" key
 	 *
 	 * @since 5.2
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevWalk.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevWalk.java
index 5d5ba12baa..d5b3643af9 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevWalk.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevWalk.java
@@ -527,10 +527,12 @@ public class RevWalk implements Iterable<RevCommit>, AutoCloseable {
 	private List<Ref> getMergedInto(RevCommit needle, Collection<Ref> haystacks,
 				Enum returnStrategy, ProgressMonitor monitor) throws IOException {
 		List<Ref> result = new ArrayList<>();
+		List<RevCommit> uninteresting = new ArrayList<>();
 		RevFilter oldRF = filter;
 		TreeFilter oldTF = treeFilter;
 		try {
 			finishDelayedFreeFlags();
+			reset(~freeFlags & APP_FLAGS);
 			filter = RevFilter.ALL;
 			treeFilter = TreeFilter.ALL;
 			for (Ref r: haystacks) {
@@ -559,13 +561,14 @@ public class RevWalk implements Iterable<RevCommit>, AutoCloseable {
 				}
 				if(!commitFound){
 					markUninteresting(c);
+					uninteresting.add(c);
 					if (returnStrategy == GetMergedIntoStrategy.RETURN_ON_FIRST_NOT_FOUND) {
 						return result;
 					}
 				}
 			}
 		} finally {
-			reset(~freeFlags & APP_FLAGS);
+			roots.addAll(uninteresting);
 			filter = oldRF;
 			treeFilter = oldTF;
 		}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/GitProtocolConstants.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/GitProtocolConstants.java
index c5e52bef98..aaa9308ac3 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/GitProtocolConstants.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/GitProtocolConstants.java
@@ -255,6 +255,13 @@ public final class GitProtocolConstants {
 	public static final String COMMAND_FETCH = "fetch"; //$NON-NLS-1$
 
 	/**
+	 * The server supports the object-info capability.
+	 *
+	 * @since 5.13
+	 */
+	public static final String COMMAND_OBJECT_INFO = "object-info"; //$NON-NLS-1$
+
+	/**
 	 * HTTP header to set by clients to request a specific git protocol version
 	 * in the HTTP transport.
 	 *
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/ObjectInfoRequest.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/ObjectInfoRequest.java
new file mode 100644
index 0000000000..86a2716675
--- /dev/null
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/ObjectInfoRequest.java
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2021, Google LLC. and others
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Distribution License v. 1.0 which is available at
+ * https://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+package org.eclipse.jgit.transport;
+
+import java.util.Collections;
+import java.util.List;
+
+import org.eclipse.jgit.lib.ObjectId;
+
+/**
+ * object-info request.
+ *
+ * <p>
+ * This is the parsed request for an object-info call, used as input to
+ * {@link ProtocolV2Hook}.
+ *
+ * @see <a href=
+ *      "https://www.kernel.org/pub/software/scm/git/docs/technical/protocol-v2.html#_object_info">object-info
+ *      documentation</a>
+ *
+ * @since 5.13
+ */
+public final class ObjectInfoRequest {
+	private final List<ObjectId> objectIDs;
+
+	private ObjectInfoRequest(List<ObjectId> objectIDs) {
+		this.objectIDs = objectIDs;
+	}
+
+	/** @return object IDs that the client requested. */
+	public List<ObjectId> getObjectIDs() {
+		return this.objectIDs;
+	}
+
+	/** @return A builder of {@link ObjectInfoRequest}. */
+	public static Builder builder() {
+		return new Builder();
+	}
+
+	/** A builder for {@link ObjectInfoRequest}. */
+	public static final class Builder {
+		private List<ObjectId> objectIDs = Collections.emptyList();
+
+		private Builder() {
+		}
+
+		/**
+		 * @param value
+		 * @return the Builder
+		 */
+		public Builder setObjectIDs(List<ObjectId> value) {
+			objectIDs = value;
+			return this;
+		}
+
+		/** @return ObjectInfoRequest */
+		public ObjectInfoRequest build() {
+			return new ObjectInfoRequest(
+					Collections.unmodifiableList(objectIDs));
+		}
+	}
+}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV2Hook.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV2Hook.java
index bfa7490665..d7626df3fa 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV2Hook.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV2Hook.java
@@ -55,4 +55,16 @@ public interface ProtocolV2Hook {
 			throws ServiceMayNotContinueException {
 		// Do nothing by default
 	}
+
+	/**
+	 * @param req
+	 *            the object-info request
+	 * @throws ServiceMayNotContinueException
+	 *             abort; the message will be sent to the user
+	 * @since 5.13
+	 */
+	default void onObjectInfo(ObjectInfoRequest req)
+			throws ServiceMayNotContinueException {
+		// Do nothing by default
+	}
 }
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV2HookChain.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV2HookChain.java
index 4cf8db6f5e..7b3a4cea06 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV2HookChain.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV2HookChain.java
@@ -71,6 +71,14 @@ public class ProtocolV2HookChain implements ProtocolV2Hook {
 		}
 	}
 
+	@Override
+	public void onObjectInfo(ObjectInfoRequest req)
+			throws ServiceMayNotContinueException {
+		for (ProtocolV2Hook hook : hooks) {
+			hook.onObjectInfo(req);
+		}
+	}
+
 	private ProtocolV2HookChain(List<? extends ProtocolV2Hook> hooks) {
 		this.hooks = Collections.unmodifiableList(hooks);
 	}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV2Parser.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV2Parser.java
index 92f0133f5a..6cec4b9a3f 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV2Parser.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV2Parser.java
@@ -28,6 +28,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.function.Consumer;
 
+import org.eclipse.jgit.errors.InvalidObjectIdException;
 import org.eclipse.jgit.errors.PackProtocolException;
 import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.lib.ObjectId;
@@ -248,4 +249,38 @@ final class ProtocolV2Parser {
 		return builder.setRefPrefixes(prefixes).build();
 	}
 
+	ObjectInfoRequest parseObjectInfoRequest(PacketLineIn pckIn)
+			throws PackProtocolException, IOException {
+		ObjectInfoRequest.Builder builder = ObjectInfoRequest.builder();
+		List<ObjectId> objectIDs = new ArrayList<>();
+
+		String line = pckIn.readString();
+
+		if (PacketLineIn.isEnd(line)) {
+			return builder.build();
+		}
+
+		if (!line.equals("size")) { //$NON-NLS-1$
+			throw new PackProtocolException(MessageFormat
+					.format(JGitText.get().unexpectedPacketLine, line));
+		}
+
+		for (String line2 : pckIn.readStrings()) {
+			if (!line2.startsWith("oid ")) { //$NON-NLS-1$
+				throw new PackProtocolException(MessageFormat
+						.format(JGitText.get().unexpectedPacketLine, line2));
+			}
+
+			String oidStr = line2.substring("oid ".length()); //$NON-NLS-1$
+
+			try {
+				objectIDs.add(ObjectId.fromString(oidStr));
+			} catch (InvalidObjectIdException e) {
+				throw new PackProtocolException(MessageFormat
+						.format(JGitText.get().invalidObject, oidStr), e);
+			}
+		}
+
+		return builder.setObjectIDs(objectIDs).build();
+	}
 }
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/ReceivePack.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/ReceivePack.java
index 79f60c3202..58f8895e00 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/ReceivePack.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/ReceivePack.java
@@ -29,6 +29,7 @@ import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.io.UncheckedIOException;
 import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -37,6 +38,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 
 import org.eclipse.jgit.annotations.Nullable;
 import org.eclipse.jgit.errors.InvalidObjectIdException;
@@ -441,7 +444,7 @@ public class ReceivePack {
 	 */
 	public void setAdvertisedRefs(Map<String, Ref> allRefs,
 			Set<ObjectId> additionalHaves) {
-		refs = allRefs != null ? allRefs : db.getAllRefs();
+		refs = allRefs != null ? allRefs : getAllRefs();
 		refs = refFilter.filter(refs);
 		advertisedHaves.clear();
 
@@ -1296,6 +1299,21 @@ public class ReceivePack {
 	}
 
 	/**
+	 * Extract the full list of refs from the ref-db.
+	 *
+	 * @return Map of all refname/ref
+	 */
+	private Map<String, Ref> getAllRefs() {
+		try {
+			return db.getRefDatabase().getRefs().stream()
+					.collect(Collectors.toMap(Ref::getName,
+							Function.identity()));
+		} catch (IOException e) {
+			throw new UncheckedIOException(e);
+		}
+	}
+
+	/**
 	 * Receive a list of commands from the input.
 	 *
 	 * @throws java.io.IOException
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransferConfig.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransferConfig.java
index da97f1e580..02be434887 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransferConfig.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransferConfig.java
@@ -123,6 +123,7 @@ public class TransferConfig {
 
 	private final boolean advertiseSidebandAll;
 	private final boolean advertiseWaitForDone;
+	private final boolean advertiseObjectInfo;
 
 	final @Nullable ProtocolVersion protocolVersion;
 	final String[] hideRefs;
@@ -211,6 +212,8 @@ public class TransferConfig {
 				"advertisesidebandall", false);
 		advertiseWaitForDone = rc.getBoolean("uploadpack",
 				"advertisewaitfordone", false);
+		advertiseObjectInfo = rc.getBoolean("uploadpack",
+				"advertiseobjectinfo", false);
 	}
 
 	/**
@@ -318,6 +321,14 @@ public class TransferConfig {
 	}
 
 	/**
+	 * @return true to advertise object-info to all clients
+	 * @since 5.13
+	 */
+	public boolean isAdvertiseObjectInfo() {
+		return advertiseObjectInfo;
+	}
+
+	/**
 	 * Get {@link org.eclipse.jgit.transport.RefFilter} respecting configured
 	 * hidden refs.
 	 *
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/UploadPack.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/UploadPack.java
index 37a1c1e589..07b348d0e7 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/UploadPack.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/UploadPack.java
@@ -17,6 +17,7 @@ import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_REF_IN_
 import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_SERVER_OPTION;
 import static org.eclipse.jgit.transport.GitProtocolConstants.COMMAND_FETCH;
 import static org.eclipse.jgit.transport.GitProtocolConstants.COMMAND_LS_REFS;
+import static org.eclipse.jgit.transport.GitProtocolConstants.COMMAND_OBJECT_INFO;
 import static org.eclipse.jgit.transport.GitProtocolConstants.OPTION_AGENT;
 import static org.eclipse.jgit.transport.GitProtocolConstants.OPTION_ALLOW_REACHABLE_SHA1_IN_WANT;
 import static org.eclipse.jgit.transport.GitProtocolConstants.OPTION_ALLOW_TIP_SHA1_IN_WANT;
@@ -1269,6 +1270,32 @@ public class UploadPack {
 		}
 	}
 
+	private void objectInfo(PacketLineOut pckOut) throws IOException {
+		ProtocolV2Parser parser = new ProtocolV2Parser(transferConfig);
+		ObjectInfoRequest req = parser.parseObjectInfoRequest(pckIn);
+
+		protocolV2Hook.onObjectInfo(req);
+
+		ObjectReader or = getRepository().newObjectReader();
+
+		// Size is the only attribute currently supported.
+		pckOut.writeString("size"); //$NON-NLS-1$
+
+		for (ObjectId oid : req.getObjectIDs()) {
+			long size;
+			try {
+				size = or.getObjectSize(oid, ObjectReader.OBJ_ANY);
+			} catch (MissingObjectException e) {
+				throw new PackProtocolException(MessageFormat
+						.format(JGitText.get().missingObject, oid.name()), e);
+			}
+
+			pckOut.writeString(oid.getName() + " " + size); //$NON-NLS-1$
+		}
+
+		pckOut.end();
+	}
+
 	/*
 	 * Returns true if this is the last command and we should tear down the
 	 * connection.
@@ -1295,6 +1322,10 @@ public class UploadPack {
 			fetchV2(pckOut);
 			return false;
 		}
+		if (command.equals("command=" + COMMAND_OBJECT_INFO)) { //$NON-NLS-1$
+			objectInfo(pckOut);
+			return false;
+		}
 		throw new PackProtocolException(MessageFormat
 				.format(JGitText.get().unknownTransportCommand, command));
 	}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/FS.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/FS.java
index 0946f645fb..31a05933c8 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/util/FS.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/FS.java
@@ -524,7 +524,7 @@ public abstract class FS {
 		}
 
 		private static String read(Path p) throws IOException {
-			final byte[] body = IO.readFully(p.toFile());
+			byte[] body = IO.readFully(p.toFile());
 			return new String(body, 0, body.length, UTF_8);
 		}
 
@@ -766,7 +766,7 @@ public abstract class FS {
 		}
 
 		private static String getConfigKey(FileStore s) {
-			final String storeKey;
+			String storeKey;
 			if (SystemReader.getInstance().isWindows()) {
 				Object attribute = null;
 				try {
@@ -1164,7 +1164,7 @@ public abstract class FS {
 	 *         platform does not require path name translation.
 	 */
 	public File resolve(File dir, String name) {
-		final File abspn = new File(name);
+		File abspn = new File(name);
 		if (abspn.isAbsolute())
 			return abspn;
 		return new File(dir, name);
@@ -1257,7 +1257,7 @@ public abstract class FS {
 	}
 
 	private File defaultUserHomeImpl() {
-		final String home = AccessController.doPrivileged(
+		String home = AccessController.doPrivileged(
 				(PrivilegedAction<String>) () -> System.getProperty("user.home") //$NON-NLS-1$
 		);
 		if (home == null || home.length() == 0)
@@ -1267,7 +1267,8 @@ public abstract class FS {
 
 	/**
 	 * Searches the given path to see if it contains one of the given files.
-	 * Returns the first it finds. Returns null if not found or if path is null.
+	 * Returns the first it finds which is executable. Returns null if not found
+	 * or if path is null.
 	 *
 	 * @param path
 	 *            List of paths to search separated by File.pathSeparator
@@ -1277,14 +1278,15 @@ public abstract class FS {
 	 * @since 3.0
 	 */
 	protected static File searchPath(String path, String... lookFor) {
-		if (path == null)
+		if (path == null) {
 			return null;
+		}
 
 		for (String p : path.split(File.pathSeparator)) {
 			for (String command : lookFor) {
-				final File file = new File(p, command);
+				File file = new File(p, command);
 				try {
-					if (file.isFile()) {
+					if (file.isFile() && file.canExecute()) {
 						return file.getAbsoluteFile();
 					}
 				} catch (SecurityException e) {
@@ -1339,7 +1341,7 @@ public abstract class FS {
 	protected static String readPipe(File dir, String[] command,
 			String encoding, Map<String, String> env)
 			throws CommandFailedException {
-		final boolean debug = LOG.isDebugEnabled();
+		boolean debug = LOG.isDebugEnabled();
 		try {
 			if (debug) {
 				LOG.debug("readpipe " + Arrays.asList(command) + "," //$NON-NLS-1$ //$NON-NLS-2$
@@ -1806,11 +1808,11 @@ public abstract class FS {
 	 * @since 5.0
 	 */
 	public Entry[] list(File directory, FileModeStrategy fileModeStrategy) {
-		final File[] all = directory.listFiles();
+		File[] all = directory.listFiles();
 		if (all == null) {
 			return NO_ENTRIES;
 		}
-		final Entry[] result = new Entry[all.length];
+		Entry[] result = new Entry[all.length];
 		for (int i = 0; i < result.length; i++) {
 			result[i] = new FileEntry(all[i], this, fileModeStrategy);
 		}
@@ -1840,10 +1842,9 @@ public abstract class FS {
 	 * @since 4.0
 	 */
 	public ProcessResult runHookIfPresent(Repository repository,
-			final String hookName,
-			String[] args) throws JGitInternalException {
-		return runHookIfPresent(repository, hookName, args, System.out, System.err,
-				null);
+			String hookName, String[] args) throws JGitInternalException {
+		return runHookIfPresent(repository, hookName, args, System.out,
+				System.err, null);
 	}
 
 	/**
@@ -1875,9 +1876,9 @@ public abstract class FS {
 	 * @since 5.11
 	 */
 	public ProcessResult runHookIfPresent(Repository repository,
-			final String hookName,
-			String[] args, OutputStream outRedirect, OutputStream errRedirect,
-			String stdinArgs) throws JGitInternalException {
+			String hookName, String[] args, OutputStream outRedirect,
+			OutputStream errRedirect, String stdinArgs)
+			throws JGitInternalException {
 		return new ProcessResult(Status.NOT_SUPPORTED);
 	}
 
@@ -1911,7 +1912,7 @@ public abstract class FS {
 	 * @since 5.11
 	 */
 	protected ProcessResult internalRunHookIfPresent(Repository repository,
-			final String hookName, String[] args, OutputStream outRedirect,
+			String hookName, String[] args, OutputStream outRedirect,
 			OutputStream errRedirect, String stdinArgs)
 			throws JGitInternalException {
 		File hookFile = findHook(repository, hookName);
@@ -2107,7 +2108,7 @@ public abstract class FS {
 			OutputStream outRedirect, OutputStream errRedirect,
 			InputStream inRedirect) throws IOException,
 			InterruptedException {
-		final ExecutorService executor = Executors.newFixedThreadPool(2);
+		ExecutorService executor = Executors.newFixedThreadPool(2);
 		Process process = null;
 		// We'll record the first I/O exception that occurs, but keep on trying
 		// to dispose of our open streams and file handles