Fix handling of missing pack index file

As demonstrated in
`UploadPackHandleDeletedPackFile.testV2IdxFileRemovedDuringUploadPack`
the fetch operation will fail when the pack index file is removed.

This is due to a wrapping of `FileNotFoundException` (which is a
subclass of `IOExeption`) in an `IOException` at PackIndex L#68. This
is then changing the behaviour of error handling in
`Pack.file.getBitmapIndex()` where the `FileNotFoundException` is
swallowed and allows the fetch process to continue. With FNFE being
wrapped in IOE, this blows up and breaks the fetch operation.

Simply rethrowing `FileNotFoundException` from `PackFile.open()` fixes
the broken fetch operation. This will also mark the whole pack as
invalid in the `IOException` handler in `Pack.idx()` method.

Change-Id: Ibe321aa1af21d26500e1cb2eb3464cc99a6dbc62
Signed-off-by: Dariusz Luksza <dariusz.luksza@gmail.com>
(cherry picked from commit e0910eda3ea1c474b4cf9b00ac698f739a982f8c)

3 files changed, 6 insertions, 6 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackHandleDeletedPackFileTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackHandleDeletedPackFileTest.java
index b1c9447c7f..417ce61df2 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackHandleDeletedPackFileTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/UploadPackHandleDeletedPackFileTest.java
@@ -32,7 +32,6 @@ import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.transport.UploadPack.RequestPolicy;
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;
@@ -80,7 +79,6 @@ public class UploadPackHandleDeletedPackFileTest
 	}
 
 	@Test
-	@Ignore("pending fix")
 	public void testV2IdxFileRemovedDuringUploadPack() throws Exception {
 		doRemovePackFileDuringUploadPack(PackExt.INDEX);
 	}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/Pack.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/Pack.java
index 6e74136c1b..29f936587d 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/Pack.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/Pack.java
@@ -1129,9 +1129,9 @@ public class Pack implements Iterable<PackIndex.MutableEntry> {
 				idx = PackBitmapIndex.open(bitmapIdxFile, idx(),
 						getReverseIdx());
 			} catch (FileNotFoundException e) {
-				// Once upon a time this bitmap file existed. Now it
-				// has been removed. Most likely an external gc  has
-				// removed this packfile and the bitmap
+				// Once upon a time the bitmap or index files existed. Now one
+				// of them has been removed. Most likely an external gc has
+				// removed index, packfile or the bitmap
 				bitmapIdxFile = null;
 				return null;
 			}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackIndex.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackIndex.java
index f4f62d4205..c0689dc634 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackIndex.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackIndex.java
@@ -64,7 +64,9 @@ public abstract class PackIndex
 	public static PackIndex open(File idxFile) throws IOException {
 		try (SilentFileInputStream fd = new SilentFileInputStream(
 				idxFile)) {
-				return read(fd);
+			return read(fd);
+		} catch (FileNotFoundException e) {
+			throw e;
 		} catch (IOException ioe) {
 			throw new IOException(
 					MessageFormat.format(JGitText.get().unreadablePackIndex,