Merge branch 'stable-5.10' into stable-5.11

* stable-5.10:
  Add missing since tag for SshTestHarness#publicKey2
  Silence API errors
  Prevent infinite loop rescanning the pack list on
PackMismatchException
  Remove blank in maven.config

Migrated "Prevent infinite loop rescanning the pack list on
PackMismatchException" to refactoring done in
https://git.eclipse.org/r/q/topic:restore-preserved-packs

Change-Id: I0fb77bb9b498d48d5da88a93486b99bf8121e3bd

3 files changed, 58 insertions, 6 deletions

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/errors/PackMismatchException.java b/org.eclipse.jgit/src/org/eclipse/jgit/errors/PackMismatchException.java
index 44b8e0193c..7a2c70de79 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/errors/PackMismatchException.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/errors/PackMismatchException.java
@@ -18,6 +18,8 @@ import java.io.IOException;
 public class PackMismatchException extends IOException {
 	private static final long serialVersionUID = 1L;
 
+	private boolean permanent;
+
 	/**
 	 * Construct a pack modification error.
 	 *
@@ -27,4 +29,31 @@ public class PackMismatchException extends IOException {
 	public PackMismatchException(String why) {
 		super(why);
 	}
+
+	/**
+	 * Set the type of the exception
+	 *
+	 * @param permanent
+	 *            whether the exception is considered permanent
+	 * @since 5.9.1
+	 */
+	public void setPermanent(boolean permanent) {
+		this.permanent = permanent;
+	}
+
+	/**
+	 * Check if this is a permanent problem
+	 *
+	 * @return if this is a permanent problem and repeatedly scanning the
+	 *         packlist couldn't fix it
+	 * @since 5.9.1
+	 */
+	public boolean isPermanent() {
+		return permanent;
+	}
+
+	@Override
+	public String toString() {
+		return super.toString() + ", permanent: " + permanent; //$NON-NLS-1$
+	}
 }
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/ObjectDirectory.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/ObjectDirectory.java
index 627facca02..a3ce3158ae 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/ObjectDirectory.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/ObjectDirectory.java
@@ -30,6 +30,7 @@ import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicReference;
 
+import org.eclipse.jgit.errors.PackMismatchException;
 import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.internal.storage.pack.ObjectToPack;
 import org.eclipse.jgit.internal.storage.pack.PackExt;
@@ -350,7 +351,8 @@ public class ObjectDirectory extends FileObjectDatabase {
 	}
 
 	private ObjectLoader openPackedFromSelfOrAlternate(WindowCursor curs,
-			AnyObjectId objectId, Set<AlternateHandle.Id> skips) {
+			AnyObjectId objectId, Set<AlternateHandle.Id> skips)
+			throws PackMismatchException {
 		ObjectLoader ldr = openPackedObject(curs, objectId);
 		if (ldr != null) {
 			return ldr;
@@ -386,7 +388,8 @@ public class ObjectDirectory extends FileObjectDatabase {
 		return null;
 	}
 
-	ObjectLoader openPackedObject(WindowCursor curs, AnyObjectId objectId) {
+	ObjectLoader openPackedObject(WindowCursor curs, AnyObjectId objectId)
+			throws PackMismatchException {
 		return packed.open(curs, objectId);
 	}
 
@@ -421,7 +424,8 @@ public class ObjectDirectory extends FileObjectDatabase {
 	}
 
 	private long getPackedSizeFromSelfOrAlternate(WindowCursor curs,
-			AnyObjectId id, Set<AlternateHandle.Id> skips) {
+			AnyObjectId id, Set<AlternateHandle.Id> skips)
+			throws PackMismatchException {
 		long len = packed.getSize(curs, id);
 		if (0 <= len) {
 			return len;
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackDirectory.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackDirectory.java
index 73745d8c64..73f6b4fffa 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackDirectory.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackDirectory.java
@@ -59,6 +59,8 @@ class PackDirectory {
 	private final static Logger LOG = LoggerFactory
 			.getLogger(PackDirectory.class);
 
+	private static final int MAX_PACKLIST_RESCAN_ATTEMPTS = 5;
+
 	private static final PackList NO_PACKS = new PackList(FileSnapshot.DIRTY,
 			new Pack[0]);
 
@@ -201,9 +203,11 @@ class PackDirectory {
 		return true;
 	}
 
-	ObjectLoader open(WindowCursor curs, AnyObjectId objectId) {
+	ObjectLoader open(WindowCursor curs, AnyObjectId objectId)
+			throws PackMismatchException {
 		PackList pList;
 		do {
+			int retries = 0;
 			SEARCH: for (;;) {
 				pList = packList.get();
 				for (Pack p : pList.packs) {
@@ -215,6 +219,7 @@ class PackDirectory {
 					} catch (PackMismatchException e) {
 						// Pack was modified; refresh the entire pack list.
 						if (searchPacksAgain(pList)) {
+							retries = checkRescanPackThreshold(retries, e);
 							continue SEARCH;
 						}
 					} catch (IOException e) {
@@ -227,9 +232,11 @@ class PackDirectory {
 		return null;
 	}
 
-	long getSize(WindowCursor curs, AnyObjectId id) {
+	long getSize(WindowCursor curs, AnyObjectId id)
+			throws PackMismatchException {
 		PackList pList;
 		do {
+			int retries = 0;
 			SEARCH: for (;;) {
 				pList = packList.get();
 				for (Pack p : pList.packs) {
@@ -242,6 +249,7 @@ class PackDirectory {
 					} catch (PackMismatchException e) {
 						// Pack was modified; refresh the entire pack list.
 						if (searchPacksAgain(pList)) {
+							retries = checkRescanPackThreshold(retries, e);
 							continue SEARCH;
 						}
 					} catch (IOException e) {
@@ -255,8 +263,9 @@ class PackDirectory {
 	}
 
 	void selectRepresentation(PackWriter packer, ObjectToPack otp,
-			WindowCursor curs) {
+			WindowCursor curs) throws PackMismatchException {
 		PackList pList = packList.get();
+		int retries = 0;
 		SEARCH: for (;;) {
 			for (Pack p : pList.packs) {
 				try {
@@ -268,6 +277,7 @@ class PackDirectory {
 				} catch (PackMismatchException e) {
 					// Pack was modified; refresh the entire pack list.
 					//
+					retries = checkRescanPackThreshold(retries, e);
 					pList = scanPacks(pList);
 					continue SEARCH;
 				} catch (IOException e) {
@@ -278,6 +288,15 @@ class PackDirectory {
 		}
 	}
 
+	private int checkRescanPackThreshold(int retries, PackMismatchException e)
+			throws PackMismatchException {
+		if (retries++ > MAX_PACKLIST_RESCAN_ATTEMPTS) {
+			e.setPermanent(true);
+			throw e;
+		}
+		return retries;
+	}
+
 	private void handlePackError(IOException e, Pack p) {
 		String warnTmpl = null;
 		int transientErrorCount = 0;