Fix keep pack filename

Previously it was looking for a keep file with the name of a pack file
(extenstion included) appended with a '.keep'. However, the keep file
name should be the pack file name  with a '.keep' extension

Change-Id: I9dc4c7c393ae20aefa0b9507df8df83610ce4d42
Signed-off-by: James Melvin <jmelvin@codeaurora.org>

org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/GcKeepFilesTest.java

@@ -73,7 +73,10 @@ public class GcKeepFilesTest extends GcTestCase {
 				.iterator();
 		PackFile singlePack = packIt.next();
 		assertFalse(packIt.hasNext());
-		File keepFile = new File(singlePack.getPackFile().getPath() + ".keep");
+		String packFileName = singlePack.getPackFile().getPath();
+		String keepFileName = packFileName.substring(0,
+				packFileName.lastIndexOf('.')) + ".keep";
+		File keepFile = new File(keepFileName);
 		assertFalse(keepFile.exists());
 		assertTrue(keepFile.createNewFile());
 		bb.commit().add("A", "A2").add("B", "B2").create();

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

@@ -46,6 +46,7 @@
 package org.eclipse.jgit.internal.storage.file;
 
 import static org.eclipse.jgit.internal.storage.pack.PackExt.BITMAP_INDEX;
+import static org.eclipse.jgit.internal.storage.pack.PackExt.KEEP;
 import static org.eclipse.jgit.internal.storage.pack.PackExt.INDEX;
 
 import java.io.EOFException;
@@ -241,7 +242,7 @@ public class PackFile implements Iterable<PackIndex.MutableEntry> {
 	 */
 	public boolean shouldBeKept() {
 		if (keepFile == null)
-			keepFile = new File(packFile.getPath() + ".keep"); //$NON-NLS-1$
+			keepFile = extFile(KEEP);
 		return keepFile.exists();
 	}
 

org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackExt.java

@@ -53,6 +53,9 @@ public class PackExt {
 	/** A pack index file extension. */
 	public static final PackExt INDEX = newPackExt("idx"); //$NON-NLS-1$
 
+	/** A keep pack file extension. */
+	public static final PackExt KEEP = newPackExt("keep"); //$NON-NLS-1$
+
 	/** A pack bitmap index file extension. */
 	public static final PackExt BITMAP_INDEX = newPackExt("bitmap"); //$NON-NLS-1$