Merge branch 'stable-5.9' into stable-5.10

* stable-5.9:
  Prevent infinite loop rescanning the pack list on
PackMismatchException
  Remove blank in maven.config

Change-Id: I15ff2d7716ecaceb0eb87b8823d85670f5db709d

.mvn/maven.config

@@ -1 +1 @@
--T 1C
+-T1C

org.eclipse.jgit/.settings/.api_filters

@@ -1,5 +1,19 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <component id="org.eclipse.jgit" version="2">
+    <resource path="src/org/eclipse/jgit/errors/PackMismatchException.java" type="org.eclipse.jgit.errors.PackMismatchException">
+        <filter id="1142947843">
+            <message_arguments>
+                <message_argument value="5.9.1"/>
+                <message_argument value="isPermanent()"/>
+            </message_arguments>
+        </filter>
+        <filter id="1142947843">
+            <message_arguments>
+                <message_argument value="5.9.1"/>
+                <message_argument value="setPermanent(boolean)"/>
+            </message_arguments>
+        </filter>
+    </resource>
     <resource path="src/org/eclipse/jgit/lib/ConfigConstants.java" type="org.eclipse.jgit.lib.ConfigConstants">
         <filter id="1141899266">
             <message_arguments>

org.eclipse.jgit/src/org/eclipse/jgit/errors/PackMismatchException.java

@@ -18,6 +18,8 @@
 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; //$NON-NLS-1$
+	}
 }

org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/ObjectDirectory.java

@@ -89,6 +89,8 @@ public class ObjectDirectory extends FileObjectDatabase {
 	 *  handle exception is thrown */
 	final static int MAX_LOOSE_OBJECT_STALE_READ_ATTEMPTS = 5;
 
+	private static final int MAX_PACKLIST_RESCAN_ATTEMPTS = 5;
+
 	private final AlternateHandle handle = new AlternateHandle(this);
 
 	private final Config config;
@@ -413,7 +415,8 @@ ObjectLoader openObject(WindowCursor curs, AnyObjectId objectId)
 	}
 
 	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;
@@ -449,9 +452,11 @@ private ObjectLoader openLooseFromSelfOrAlternate(WindowCursor curs,
 		return null;
 	}
 
-	ObjectLoader openPackedObject(WindowCursor curs, AnyObjectId objectId) {
+	ObjectLoader openPackedObject(WindowCursor curs, AnyObjectId objectId)
+			throws PackMismatchException {
 		PackList pList;
 		do {
+			int retries = 0;
 			SEARCH: for (;;) {
 				pList = packList.get();
 				for (PackFile p : pList.packs) {
@@ -462,8 +467,10 @@ ObjectLoader openPackedObject(WindowCursor curs, AnyObjectId objectId) {
 							return ldr;
 					} catch (PackMismatchException e) {
 						// Pack was modified; refresh the entire pack list.
-						if (searchPacksAgain(pList))
+						if (searchPacksAgain(pList)) {
+							retries = checkRescanPackThreshold(retries, e);
 							continue SEARCH;
+						}
 					} catch (IOException e) {
 						handlePackError(e, p);
 					}
@@ -555,7 +562,8 @@ long getObjectSize(WindowCursor curs, AnyObjectId id)
 	}
 
 	private long getPackedSizeFromSelfOrAlternate(WindowCursor curs,
-			AnyObjectId id, Set<AlternateHandle.Id> skips) {
+			AnyObjectId id, Set<AlternateHandle.Id> skips)
+			throws PackMismatchException {
 		long len = getPackedObjectSize(curs, id);
 		if (0 <= len) {
 			return len;
@@ -590,9 +598,11 @@ private long getLooseSizeFromSelfOrAlternate(WindowCursor curs,
 		return -1;
 	}
 
-	private long getPackedObjectSize(WindowCursor curs, AnyObjectId id) {
+	private long getPackedObjectSize(WindowCursor curs, AnyObjectId id)
+			throws PackMismatchException {
 		PackList pList;
 		do {
+			int retries = 0;
 			SEARCH: for (;;) {
 				pList = packList.get();
 				for (PackFile p : pList.packs) {
@@ -603,8 +613,10 @@ private long getPackedObjectSize(WindowCursor curs, AnyObjectId id) {
 							return len;
 					} catch (PackMismatchException e) {
 						// Pack was modified; refresh the entire pack list.
-						if (searchPacksAgain(pList))
+						if (searchPacksAgain(pList)) {
+							retries = checkRescanPackThreshold(retries, e);
 							continue SEARCH;
+						}
 					} catch (IOException e) {
 						handlePackError(e, p);
 					}
@@ -639,6 +651,7 @@ void selectObjectRepresentation(PackWriter packer, ObjectToPack otp,
 	private void selectObjectRepresentation(PackWriter packer, ObjectToPack otp,
 			WindowCursor curs, Set<AlternateHandle.Id> skips) throws IOException {
 		PackList pList = packList.get();
+		int retries = 0;
 		SEARCH: for (;;) {
 			for (PackFile p : pList.packs) {
 				try {
@@ -649,6 +662,7 @@ private void selectObjectRepresentation(PackWriter packer, ObjectToPack otp,
 				} catch (PackMismatchException e) {
 					// Pack was modified; refresh the entire pack list.
 					//
+					retries = checkRescanPackThreshold(retries, e);
 					pList = scanPacks(pList);
 					continue SEARCH;
 				} catch (IOException e) {
@@ -666,6 +680,15 @@ private void selectObjectRepresentation(PackWriter packer, ObjectToPack otp,
 		}
 	}
 
+	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, PackFile p) {
 		String warnTmpl = null;
 		int transientErrorCount = 0;