Merge branch 'stable-6.1' into stable-6.2

* stable-6.1:
  Add missing since tag for SshBasicTestBase
  Add missing since tag for SshTestHarness#publicKey2
  Silence API errors
  Prevent infinite loop rescanning the pack list on PackMismatchException
  Remove blank in maven.config

Change-Id: I4c5b000b09287cc32f0e4d6a24a766ef4e17ddbe

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 531fd78cd0..ac3a553279 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;
@@ -364,7 +365,8 @@ 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;
@@ -400,7 +402,8 @@ 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);
 	}
 
@@ -435,7 +438,8 @@ 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 a7f28c6778..6a99cb3d83 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
@@ -60,6 +60,8 @@ 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]);
 
@@ -209,9 +211,11 @@ 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) {
@@ -223,6 +227,7 @@ 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) {
@@ -235,9 +240,11 @@ 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) {
@@ -250,6 +257,7 @@ 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) {
@@ -263,8 +271,9 @@ 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 {
@@ -279,6 +288,7 @@ 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) {
@@ -289,6 +299,15 @@ 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;