[EGIT PATCH 07/10] Return nothing if no version exists for a commit.

[Robin Rosenberg <robin.rosenberg@dewire.com>]

I used a null reference to mean two things, which meant the
working directory version was retrieved for comparing files
when a commit did not include a named blob.

Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>
---

 .../src/org/spearce/egit/core/GitStorage.java      |   17 ++++++++++++-----
 1 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/org.spearce.egit.core/src/org/spearce/egit/core/GitStorage.java b/org.spearce.egit.core/src/org/spearce/egit/core/GitStorage.java
index e53fd83..ce4ff71 100644
--- a/org.spearce.egit.core/src/org/spearce/egit/core/GitStorage.java
+++ b/org.spearce.egit.core/src/org/spearce/egit/core/GitStorage.java
@@ -41,7 +41,10 @@ public class GitStorage implements IStorage {
 
 	private TreeEntry entry;
 
+	private ObjectId treeId;
+
 	public GitStorage(ObjectId treeId, IResource resource) {
+		this.treeId = treeId;
 		this.resource = resource;
 		if (treeId == null)
 			return;
@@ -68,13 +71,17 @@ public class GitStorage implements IStorage {
 
 	public InputStream getContents() throws CoreException {
 		try {
-			if (entry == null) {
+			if (treeId == null) {
 				return ((IFile) resource).getContents();
 			} else {
-				ObjectId id = entry.getId();
-				ObjectLoader reader = entry.getRepository().openBlob(id);
-				byte[] bytes = reader.getBytes();
-				return new ByteArrayInputStream(bytes);
+				if (entry == null)
+					return new ByteArrayInputStream(new byte[0]);
+				else {
+					ObjectId id = entry.getId();
+					ObjectLoader reader = entry.getRepository().openBlob(id);
+					byte[] bytes = reader.getBytes();
+					return new ByteArrayInputStream(bytes);
+				}
 			}
 		} catch (FileNotFoundException e) {
 			throw new ResourceException(IResourceStatus.FAILED_READ_LOCAL,