Fix PackWriterBitmapWalker handling non-existing uninteresting objects When writing new packs it should be allowed to specify objects as "have" (objects which should not be included in the pack) which do not exist in the local repository. This works with the traditional PackWriter, but when PackWriter was working on a repository with bitmap indexes and used PackWriterBitmapWalker then this feature was broken. Non-existing "have" objects lead to MissingObjectExceptions. That broke push and Gerrit replication. When the replication target had branches unknown to the replication source then the source repository wanted to build pack files where "have" included branch-tips which were unknown in the source repository. Bug: 427107 Change-Id: I6b6598a1ec49af68aa77ea6f1f06e827982ea4ac Also-by: Matthias Sohn <matthias.sohn@sap.com>

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/PackWriterTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/PackWriterTest.java
index aba48bc..873b2cd 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/PackWriterTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/PackWriterTest.java

@@ -54,6 +54,7 @@
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.text.ParseException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -225,6 +226,25 @@ public void testIgnoreNonExistingObjects() throws IOException {
 	}
 
 	/**
+	 * Try to pass non-existing object as uninteresting, with ignoring setting.
+	 * Use a repo with bitmap indexes because then PackWriter will use
+	 * PackWriterBitmapWalker which had problems with this situation.
+	 *
+	 * @throws IOException
+	 * @throws ParseException
+	 */
+	@Test
+	public void testIgnoreNonExistingObjectsWithBitmaps() throws IOException,
+			ParseException {
+		final ObjectId nonExisting = ObjectId
+				.fromString("0000000000000000000000000000000000000001");
+		new GC(db).gc();
+		createVerifyOpenPack(EMPTY_SET_OBJECT,
+				Collections.singleton(nonExisting), false, true, true);
+		// shouldn't throw anything
+	}
+
+	/**
 	 * Create pack basing on only interesting objects, then precisely verify
 	 * content. No delta reuse here.
 	 *
@@ -604,8 +624,17 @@ private void createVerifyOpenPack(final Set<ObjectId> interestings,
 			final Set<ObjectId> uninterestings, final boolean thin,
 			final boolean ignoreMissingUninteresting)
 			throws MissingObjectException, IOException {
+		createVerifyOpenPack(interestings, uninterestings, thin,
+				ignoreMissingUninteresting, false);
+	}
+
+	private void createVerifyOpenPack(final Set<ObjectId> interestings,
+			final Set<ObjectId> uninterestings, final boolean thin,
+			final boolean ignoreMissingUninteresting, boolean useBitmaps)
+			throws MissingObjectException, IOException {
 		NullProgressMonitor m = NullProgressMonitor.INSTANCE;
 		writer = new PackWriter(config, db.newObjectReader());
+		writer.setUseBitmaps(useBitmaps);
 		writer.setThin(thin);
 		writer.setIgnoreMissingUninteresting(ignoreMissingUninteresting);
 		writer.preparePack(m, interestings, uninterestings);

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriter.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriter.java
index f3791e6..76e0b35 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriter.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriter.java

@@ -1846,9 +1846,10 @@ private void findObjectsToPackUsingBitmaps(
 			Set<? extends ObjectId> have)
 			throws MissingObjectException, IncorrectObjectTypeException,
 			IOException {
-		BitmapBuilder haveBitmap = bitmapWalker.findObjects(have, null);
+		BitmapBuilder haveBitmap = bitmapWalker.findObjects(have, null, true);
 		bitmapWalker.reset();
-		BitmapBuilder wantBitmap = bitmapWalker.findObjects(want, haveBitmap);
+		BitmapBuilder wantBitmap = bitmapWalker.findObjects(want, haveBitmap,
+				false);
 		BitmapBuilder needBitmap = wantBitmap.andNot(haveBitmap);
 
 		if (useCachedPacks && reuseSupport != null
@@ -2048,7 +2049,7 @@ public boolean prepareBitmapIndex(ProgressMonitor pm) throws IOException {
 				walker = bitmapPreparer.newBitmapWalker();
 
 			BitmapBuilder bitmap = walker.findObjects(
-					Collections.singleton(cmit), null);
+					Collections.singleton(cmit), null, false);
 
 			if (last != null && cmit.isReuseWalker() && !bitmap.contains(last))
 				throw new IllegalStateException(MessageFormat.format(

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriterBitmapWalker.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriterBitmapWalker.java
index 2e9ce1d..63a91cd 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriterBitmapWalker.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriterBitmapWalker.java

@@ -78,7 +78,7 @@ final class PackWriterBitmapWalker {
 		this.pm = (pm == null) ? NullProgressMonitor.INSTANCE : pm;
 	}
 
-	BitmapBuilder findObjects(Set<? extends ObjectId> start, BitmapBuilder seen)
+	BitmapBuilder findObjects(Set<? extends ObjectId> start, BitmapBuilder seen, boolean ignoreMissingStart)
 			throws MissingObjectException, IncorrectObjectTypeException,
 			IOException {
 		final BitmapBuilder bitmapResult = bitmapIndex.newBitmapBuilder();
@@ -91,9 +91,15 @@ BitmapBuilder findObjects(Set<? extends ObjectId> start, BitmapBuilder seen)
 
 		boolean marked = false;
 		for (ObjectId obj : start) {
-			if (!bitmapResult.contains(obj)) {
-				walker.markStart(walker.parseAny(obj));
-				marked = true;
+			try {
+				if (!bitmapResult.contains(obj)) {
+					walker.markStart(walker.parseAny(obj));
+					marked = true;
+				}
+			} catch (MissingObjectException e) {
+				if (ignoreMissingStart)
+					continue;
+				throw e;
 			}
 		}